idnits 2.17.1 draft-ietf-calsch-ical-11.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** Looks like you're using RFC 2026 boilerplate. This must be updated to follow RFC 3978/3979, as updated by RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- ** Missing expiration date. The document expiration date should appear on the first and last page. ** The document seems to lack a 1id_guidelines paragraph about Internet-Drafts being working documents. ** The document seems to lack a 1id_guidelines paragraph about 6 months document validity -- however, there's a paragraph with a matching beginning. 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All references will be assumed normative when checking for downward references. ** There are 7 instances of too long lines in the document, the longest one being 5 characters in excess of 72. ** The abstract seems to contain references ([ICMS], [RFC2048], [ITIP]), which it shouldn't. Please replace those with straight textual mentions of the documents in question. == There are 1 instance of lines with non-RFC2606-compliant FQDNs in the document. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the RFC 3978 Section 5.4 Copyright Line does not match the current year == Line 2893 has weird spacing: '...he base offse...' == Line 3799 has weird spacing: '...ld this meeti...' == The document seems to lack the recommended RFC 2119 boilerplate, even if it appears to use RFC 2119 keywords -- however, there's a paragraph with a matching beginning. Boilerplate error? (The document does seem to have the reference to RFC 2119 which the ID-Checklist requires). == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'SHOULD not' in this paragraph: This property SHOULD not be used to alter the interpretation of an iCalendar object beyond the semantics specified in this memo. For example, it is not to be used to further the understanding of non-standard properties. == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: The property parameter CN is for the common or displayable name associated with the calendar address; ROLE, for the intended role that the attendee will have in the calendar component; PARTSTAT, for the status of the attendee's participation; RSVP, for indicating whether the favor of a reply is requested; CUTYPE, to indicate the type of calendar user; MEMBER, to indicate the groups that the attendee belongs to; DELEGATED-TO, to indicate the calendar users that the original request was delegated to; and DELEGATED-FROM, to indicate whom the request was delegated from; SENT-BY, to indicate whom is acting on behalf of the ATTENDEE; and DIR, to indicate the URI that points to the directory information corresponding to the attendee. These property parameters can be specified on an "ATTENDEE" property in either a "VEVENT", "VTODO" or "VJOURNAL" calendar component. They MUST not be specified in an "ATTENDEE" property in a "VFREEBUSY" or "VALARM" calendar component. If the LANGUAGE property parameter is specified, the identified language applies to the CN parameter. -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (September 15, 1998) is 9355 days in the past. Is this intentional? 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'ITIP' -- Possible downref: Non-RFC (?) normative reference: ref. 'ISO 8601' -- Possible downref: Non-RFC (?) normative reference: ref. 'ISO 9070' -- Possible downref: Non-RFC (?) normative reference: ref. 'MIME DIR' ** Obsolete normative reference: RFC 822 (Obsoleted by RFC 2822) ** Obsolete normative reference: RFC 1738 (Obsoleted by RFC 4248, RFC 4266) ** Obsolete normative reference: RFC 1766 (Obsoleted by RFC 3066, RFC 3282) ** Obsolete normative reference: RFC 2048 (Obsoleted by RFC 4288, RFC 4289) ** Obsolete normative reference: RFC 2111 (Obsoleted by RFC 2392) ** Obsolete normative reference: RFC 2234 (Obsoleted by RFC 4234) ** Obsolete normative reference: RFC 2279 (Obsoleted by RFC 3629) -- Possible downref: Non-RFC (?) normative reference: ref. 'TZ' -- Possible downref: Non-RFC (?) normative reference: ref. 'VCARD' -- Possible downref: Non-RFC (?) normative reference: ref. 'VCAL' -- Possible downref: Non-RFC (?) normative reference: ref. 'XAPIA' Summary: 18 errors (**), 0 flaws (~~), 15 warnings (==), 12 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group Frank Dawson, Lotus 3 Internet Draft Derik Stenerson, Microsoft 4 5 Expires six months after: September 15, 1998 7 Internet Calendaring and Scheduling Core Object Specification 8 (iCalendar) 10 Status of this Memo 12 This memo is an Internet-Draft. Internet-Drafts are working documents 13 of the Internet Engineering Task Force (IETF), its areas, and its 14 working groups. Note that other groups can also distribute working 15 documents as Internet-Drafts. 17 Internet-Drafts are draft documents valid for a maximum of six 18 months. Internet-Drafts can be updated, replaced, or made obsolete by 19 other documents at any time. It is not appropriate to use Internet- 20 Drafts as reference material or to cite them other than as a "working 21 draft" or "work in progress". 23 To view the entire list of current Internet-Drafts, please check the 24 "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow 25 Directories on ftp.is.co.za (Africa), ftp.nordu.net (Northern 26 Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au (Pacific 27 Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast). 29 Distribution of this memo is unlimited. 31 Copyright (C) The Internet Society 1998. All Rights Reserved. 33 Abstract 35 There is a clear need to provide and deploy interoperable calendaring 36 and scheduling services for the Internet. Current group scheduling 37 and Personal Information Management (PIM) products are being extended 38 for use across the Internet, today, in proprietary ways. This memo 39 has been defined to provide the definition of a common format for 40 openly exchanging calendaring and scheduling information across the 41 Internet. 43 This memo is formatted as a registration for a MIME media type per 44 [RFC 2048]. However, the format in this memo is equally applicable 45 for use outside of a MIME message content type. 47 The proposed media type value is 'text/calendar'. This string would 48 label a media type containing calendaring and scheduling information 49 encoded as text characters formatted in a manner outlined below. 51 This MIME media type provides a standard content type for capturing 52 calendar event, to-do and journal entry information. It also can be 53 used to convey free/busy time information. The content type is 54 suitable as a MIME message entity that can be transferred over MIME 55 based email systems, using HTTP or some other Internet transport. In 56 addition, the content type is useful as an object for interactions 57 between desktop applications using the operating system clipboard, 58 drag/drop or file systems capabilities. 60 This memo is based on the earlier work of the vCalendar specification 61 for the exchange of personal calendaring and scheduling information. 62 In order to avoid confusion with this referenced work, this memo is 63 to be known as the iCalendar specification. 65 Readers may also refer to the calendaring and scheduling model 66 defined in [ICMS] for a description of this Internet application. 68 This memo defines the format for specifying iCalendar object methods. 69 An iCalendar object method is a set of usage constraints for the 70 iCalendar object. For example, these methods might define scheduling 71 messages that request an event be scheduled, reply to an event 72 request, send a cancellation notice for an event, modify or replace 73 the definition of an event, provide a counter proposal for an 74 original event request, delegate an event request to another 75 individual, request free or busy time, reply to a free or busy time 76 request, or provide similar scheduling messages for a to-do or 77 journal entry calendar component. The iCalendar Transport-indendent 78 Interoperability Protocol (iTIP) defined in [ITIP] is one such 79 scheduling protocol. 81 Table of Contents 83 1 Introduction.........................................................6 84 2 Basic Grammar and Conventions........................................6 85 2.1 Formatting Conventions ...........................................7 86 2.2 Related Memos ....................................................8 87 2.3 International Considerations .....................................8 88 3 Registration Information.............................................8 89 3.1 Content Type .....................................................9 90 3.2 Parameters .......................................................9 91 3.3 Content Header Fields ...........................................10 92 3.4 Encoding Considerations .........................................10 93 3.5 Security Considerations .........................................10 94 3.6 Interoperability Considerations .................................11 95 3.7 Applications Which Use This Media Type ..........................11 96 3.8 Additional Information ..........................................11 97 3.9 Magic Numbers ...................................................11 98 3.10 File Extensions ................................................11 99 3.11 Contact for Further Information: ...............................12 100 3.12 Intended Usage .................................................12 101 3.13 Authors/Change Controllers .....................................12 102 4 iCalendar Object Specification......................................12 103 4.1 Content Lines ...................................................12 104 4.1.1 List and Field Separators ....................................15 105 4.1.2 Multiple Values ..............................................15 106 4.1.3 Binary Content ...............................................16 107 4.1.4 Character Set ................................................16 108 4.2 Property Parameters .............................................16 109 4.2.1 Alternate Text Representation ................................17 110 4.2.2 Common Name ..................................................18 111 4.2.3 Calendar User Type ...........................................18 112 4.2.4 Delegators ...................................................19 113 4.2.5 Delegatees ...................................................20 114 4.2.6 Directory Entry Reference ....................................20 115 4.2.7 Inline Encoding ..............................................20 116 4.2.8 Format Type ..................................................21 117 4.2.9 Free/Busy Time Type ..........................................22 118 4.2.10 Language ....................................................22 119 4.2.11 Group or List Membership ....................................23 120 4.2.12 Participation Status ........................................23 121 4.2.13 Recurrence Identifier Range .................................25 122 4.2.14 Alarm Trigger Relationship ..................................25 123 4.2.15 Relationship Type ...........................................26 124 4.2.16 Participation Role ..........................................26 125 4.2.17 RSVP Expectation ............................................27 126 4.2.18 Sent By .....................................................27 127 4.2.19 Time Zone Identifier ........................................28 128 4.2.20 Value Data Types ............................................29 129 4.3 Property Value Data Types .......................................30 130 4.3.1 Binary .......................................................30 131 4.3.2 Boolean ......................................................31 132 4.3.3 Calendar User Address ........................................31 133 4.3.4 Date .........................................................31 134 4.3.5 Date-Time ....................................................32 135 4.3.6 Duration .....................................................34 136 4.3.7 Float ........................................................34 137 4.3.8 Integer ......................................................35 138 4.3.9 Period of Time ...............................................35 139 4.3.10 Recurrence Rule .............................................36 140 4.3.11 Text ........................................................41 141 4.3.12 Time ........................................................42 142 4.3.13 URI .........................................................44 143 4.3.14 UTC Offset ..................................................45 144 4.4 iCalendar Object ................................................45 145 4.5 Property ........................................................46 146 4.6 Calendar Components .............................................46 147 4.6.1 Event Component ..............................................47 148 4.6.2 To-do Component ..............................................49 149 4.6.3 Journal Component ............................................51 150 4.6.4 Free/Busy Component ..........................................52 151 4.6.5 Time Zone Component ..........................................54 152 4.6.6 Alarm Component ..............................................61 153 4.7 Calendar Properties .............................................66 154 4.7.1 Calendar Scale ...............................................66 155 4.7.2 Method .......................................................67 156 4.7.3 Product Identifier ...........................................68 157 4.7.4 Version ......................................................68 158 4.8 Component Properties ............................................69 159 4.8.1 Descriptive Component Properties .............................69 160 4.8.1.1 Attachment ...............................................69 161 4.8.1.2 Categories ...............................................70 162 4.8.1.3 Classification ...........................................71 163 4.8.1.4 Comment ..................................................72 164 4.8.1.5 Description ..............................................73 165 4.8.1.6 Geographic Position ......................................74 166 4.8.1.7 Location .................................................75 167 4.8.1.8 Percent Complete .........................................76 168 4.8.1.9 Priority .................................................77 169 4.8.1.10 Resources ...............................................78 170 4.8.1.11 Status ..................................................79 171 4.8.1.12 Summary .................................................80 172 4.8.2 Date and Time Component Properties ...........................81 173 4.8.2.1 Date/Time Completed ......................................81 174 4.8.2.2 Date/Time End ............................................82 175 4.8.2.3 Date/Time Due ............................................83 176 4.8.2.4 Date/Time Start ..........................................84 177 4.8.2.5 Duration .................................................85 178 4.8.2.6 Free/Busy Time ...........................................85 179 4.8.2.7 Time Transparency ........................................87 180 4.8.3 Time Zone Component Properties ...............................87 181 4.8.3.1 Time Zone Identifier .....................................88 182 4.8.3.2 Time Zone Name ...........................................89 183 4.8.3.3 Time Zone Offset From ....................................89 184 4.8.3.4 Time Zone Offset To ......................................90 185 4.8.3.5 Time Zone URL ............................................91 186 4.8.4 Relationship Component Properties ............................91 187 4.8.4.1 Attendee .................................................91 188 4.8.4.2 Contact ..................................................94 189 4.8.4.3 Organizer ................................................95 190 4.8.4.4 Recurrence ID ............................................96 191 4.8.4.5 Related To ...............................................98 192 4.8.4.6 Uniform Resource Locator .................................99 193 4.8.4.7 Unique Identifier .......................................100 194 4.8.5 Recurrence Component Properties .............................101 195 4.8.5.1 Exception Date/Times ....................................101 196 4.8.5.2 Exception Rule ..........................................102 197 4.8.5.3 Recurrence Date/Times ...................................103 198 4.8.5.4 Recurrence Rule .........................................105 199 4.8.6 Alarm Component Properties ..................................112 200 4.8.6.1 Action ..................................................113 201 4.8.6.2 Repeat Count ............................................113 202 4.8.6.3 Trigger .................................................114 203 4.8.7 Change Management Component Properties ......................116 204 4.8.7.1 Date/Time Created .......................................116 205 4.8.7.2 Date/Time Stamp .........................................116 206 4.8.7.3 Last Modified ...........................................117 207 4.8.7.4 Sequence Number .........................................118 208 4.8.8 Miscellaneous Component Properties ..........................119 209 4.8.8.1 Non-standard Properties .................................119 210 4.8.8.2 Request Status ..........................................120 211 5 iCalendar Object Examples..........................................122 212 6 Recommended Practices..............................................125 213 7 Registration of Content Type Elements..............................126 214 7.1 Registration of New and Modified iCalendar Object Methods ......127 215 7.2 Registration of New Properties .................................127 216 7.2.1 Define the property .........................................127 217 7.2.2 Post the Property definition ................................128 218 7.2.3 Allow a comment period ......................................128 219 7.2.4 Submit the property for approval ............................128 220 7.3 Property Change Control ........................................129 221 8 References.........................................................129 222 9 Acknowledgments....................................................131 223 10 Authors' and Chairs' Addresses....................................131 224 11 Full Copyright Statement..........................................132 225 1 Introduction 227 The use of calendaring and scheduling has grown considerably in the 228 last decade. Enterprise and inter-enterprise business has become 229 dependent on rapid scheduling of events and actions using this 230 information technology. However, the longer term growth of 231 calendaring and scheduling, is currently limited by the lack of 232 Internet standards for the message content types that are central to 233 these knowledgeware applications. This memo is intended to progress 234 the level of interoperability possible between dissimilar calendaring 235 and scheduling applications. This memo defines a MIME content type 236 for exchanging electronic calendaring and scheduling information. The 237 Internet Calendaring and Scheduling Core Object Specification, or 238 iCalendar, allows for the capture and exchange of information 239 normally stored within a calendaring and scheduling application; such 240 as a Personal Information Manager (PIM) or a Group Scheduling 241 product. 243 The calendaring and scheduling model, defined in the [ICMS], is a 244 useful reference to terms and the general framework of this Internet 245 application. 247 The iCalendar format is suitable as an exchange format between 248 applications or systems. The format is defined in terms of a MIME 249 content type. This will enable the object to be exchanged using 250 several transports, including but not limited to SMTP, HTTP, a file 251 system, desktop interactive protocols such as the use of a memory- 252 based clipboard or drag/drop interactions, point-to-point 253 asynchronous communication, wired-network transport, or some form of 254 unwired transport such as infrared might also be used. 256 The memo also provides for the definition of iCalendar object methods 257 that will map this content type to a set of messages for supporting 258 calendaring and scheduling operations such as requesting, replying 259 to, modifying, and canceling meetings or appointments, to-dos and 260 journal entries. The iCalendar object methods can be used to define 261 other calendaring and scheduling operations such a requesting for and 262 replying with free/busy time data. Such a scheduling protocol is 263 defined in the iCalendar Transport-independent Interoperability 264 Protocol (iTIP) defined in [ITIP]. 266 The memo also includes a formal grammar for the content type based on 267 the Internet ABNF defined in [RFC 2234]. This ABNF is required for 268 the implementation of parsers and to serve as the definitive 269 reference when ambiguities or questions arise in interpreting the 270 descriptive prose definition of the memo. 272 2 Basic Grammar and Conventions 274 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 275 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY" and 276 "OPTIONAL" in this document are to be interoperated as described in 277 [RFC 2119]. 279 This memo makes use of both a descriptive prose and a more formal 280 notation for defining the calendaring and scheduling format. 282 The notation used in this memo is the ABNF notation of [RFC 2234]. 283 Readers intending on implementing this format defined in this memo 284 should be familiar with this notation in order to properly interpret 285 the specifications of this memo. 287 All numeric and hexadecimal values used in this memo are given in 288 decimal notation. 290 All names of properties, property parameters, enumerated property 291 values and property parameter values are case-insensitive. However, 292 all other property values are case-sensitive, unless otherwise 293 stated. 295 Note: All indented editorial notes, such as this one, are 296 intended to provide the reader with additional information. The 297 information is not essential to the building of an 298 implementation conformant with this memo. The information is 299 provided to highlight a particular feature or characteristic of 300 the memo. 302 The format for the iCalendar object is based on the syntax of the 303 [MIME DIR] content type. While the iCalendar object is not a profile 304 of the [MIME DIR] content type, it does reuse a number of the 305 elements from the [MIME DIR] specification. 307 2.1 Formatting Conventions 309 The mechanisms defined in this memo are defined in prose. Many of the 310 terms used to describe these have common usage that is different than 311 the standards usage of this memo. In order to reference within this 312 memo elements of the calendaring and scheduling model [ICMS], core 313 object (this memo) or interoperability protocol [ITIP] some 314 formatting conventions have been used. Calendaring and scheduling 315 roles defined by [ICMS] are referred to in quoted-strings of text 316 with the first character of each word in upper case. For example, 317 "Organizer" refers to a role of a "Calendar User" within the 318 scheduling protocol defined by [ITIP]. Calendar components defined by 319 this memo are referred to with capitalized, quoted-strings of text. 320 All calendar components start with the letter "V". For example, 321 "VEVENT" refers to the event calendar component, "VTODO" refers to 322 the to-do calendar component and "VJOURNAL" refers to the daily 323 journal calendar component. Scheduling methods defined by [ITIP] are 324 referred to with capitalized, quoted-strings of text. For example, 325 "REQUEST" refers to the method for requesting a scheduling calendar 326 component be created or modified, "REPLY" refers to the method a 327 recipient of a request uses to update their status with the 328 "Organizer" of the calendar component. 330 The properties defined by this memo are referred to with capitalized, 331 quoted-strings of text, followed by the word "property". For example, 332 "ATTENDEE" property refers to the iCalendar property used to convey 333 the calendar address of a calendar user. Property parameters defined 334 by this memo are referred to with lowercase, quoted-strings of text, 335 followed by the word "parameter". For example, "value" parameter 336 refers to the iCalendar property parameter used to override the 337 default data type for a property value. Enumerated values defined by 338 this memo are referred to with capitalized text, either alone or 339 followed by the word "value". For example, the "MINUTELY" value can 340 be used with the "FREQ" component of the "RECUR" data type to specify 341 repeating components based on an interval of one minute or more. 343 2.2 Related Memos 345 Implementers will need to be familiar with several other memos that, 346 along with this memo, form a framework for Internet calendaring and 347 scheduling standards. This memo, [ICAL], specifies a core 348 specification of objects, data types, properties and property 349 parameters. 351 [ICMS] - specifies a common terminology and abstract model; 353 [ITIP] - specifies an interoperability protocol for scheduling 354 between different implementations; 356 [IMIP] specifies an Internet email binding for [ITIP]. 358 This memo does not attempt to repeat the specification of concepts or 359 definitions from these other memos. Where possible, references are 360 made to the memo that provides for the specification of these 361 concepts or definitions. 363 2.3 International Considerations 365 In the rest of this document, descriptions of characters are of the 366 form "character name (codepoint)", where "codepoint" is from the US- 367 ASCII character set. The "character name" is the authoritative 368 description; (codepoint) is a reference to that character in US- 369 ASCII or US-ASCII compatible sets (for example the ISO-8859-x family, 370 UTF-8, ISO-2022-xx, KOI8-R). If a non-US-ASCII compatible character 371 set is used, appropriate code-point from that character set MUST be 372 chosen instead. Use of non-US-ASCII-compatible character sets is NOT 373 recommended. 375 3 Registration Information 377 The Calendaring and Scheduling Core Object Specification is intended 378 for use as a MIME content type. However, the implementation of the 379 memo is in no way limited solely as a MIME content type. 381 3.1 Content Type 383 The following text is intended to register this memo as the MIME 384 content type "text/calendar". 386 To: ietf-types@uninett.no 388 Subject: Registration of MIME content type text/calendar. 390 MIME media type name: text 392 MIME subtype name: calendar 394 3.2 Parameters 396 Required parameters: none 398 Optional parameters: charset, method, component and optinfo 400 The "charset" parameter is defined in [RFC 2046] for other body 401 parts. It is used to identify the default character set used within 402 the body part. 404 The "method" parameter is used to convey the iCalendar object method 405 or transaction semantics for the calendaring and scheduling 406 information. It also is an identifier for the restricted set of 407 properties and values that the iCalendar object consists of. The 408 parameter is to be used as a guide for applications interpreting the 409 information contained within the body part. It SHOULD NOT be used to 410 exclude or require particular pieces of information unless the 411 identified method definition specifically calls for this behavior. 412 Unless specifically forbidden by a particular method definition, a 413 text/calendar content type can contain any set of properties 414 permitted by the Calendaring and Scheduling Core Object 415 Specification. The "method" parameter MUST be the same value as that 416 specified in the "METHOD" component property in the iCalendar object. 417 If one is present, the other MUST also be present. 419 The value for the "method" parameter is defined as follows: 421 method = 1*(ALPHA / DIGIT / "-") 422 ; IANA registered iCalendar object method 424 The "component" parameter conveys the type of iCalendar calendar 425 component within the body part. If the iCalendar object contains more 426 than one calendar component type, then multiple component parameters 427 MUST be specified. 429 The value for the "component" parameter is defined as follows: 431 component = ("VEVENT" / "VTODO" / "VJOURNAL" / "VFREEBUSY" 432 / "VTIMEZONE" / x-name / iana-token) 433 The "optinfo" parameter conveys optional information about the 434 iCalendar object within the body part. This parameter can only 435 specify semantics already specified by the iCalendar object and that 436 can be otherwise determined by parsing the body part. In addition, 437 the optional information specified by this parameter MUST be 438 consistent with that information specified by the iCalendar object. 439 For example, it can be used to convey the "Attendee" response status 440 to a meeting request. The parameter value consists of a string value. 441 The parameter can be specified multiple times. 443 This parameter MAY only specify semantics already specified by the 444 iCalendar object and that can be otherwise determined by parsing the 445 body part. 447 The value for the "optinfo" parameter is defined as follows: 449 optinfo = infovalue / qinfovalue 451 infovalue = iana-token / x-name 453 qinfovalue = DQUOTE (infovalue) DQUOTE 455 3.3 Content Header Fields 457 Optional content header fields: Any header fields defined by [RFC 458 2045]. 460 3.4 Encoding Considerations 462 This MIME content type can contain 8bit characters, so the use of 463 quoted-printable or BASE64 MIME content-transfer-encodings might be 464 necessary when iCalendar objects are transferred across protocols 465 restricted to the 7bit repertoire. Note that a text valued property 466 in the content entity can also have content encoding of special 467 characters using a BACKSLASH character (US-ASCII decimal 92) 468 escapement technique. This means that content values can end up 469 encoded twice. 471 3.5 Security Considerations 473 SPOOFING - - In this memo, the "Organizer" is the only person 474 authorized to make changes to an existing "VEVENT", "VTODO", 475 "VJOURNAL" calendar component and redistribute the updates to the 476 "Attendees". An iCalendar object that maliciously changes or cancels 477 an existing "VEVENT", "VTODO" or "VJOURNAL" or "VFREEBUSY" calendar 478 component might be constructed by someone other than the "Organizer" 479 and sent to the "Attendees". In addition in this memo, other than the 480 "Organizer", an "Attendee" of a "VEVENT", "VTODO", "VJOURNAL" 481 calendar component is the only other person authorized to update any 482 parameter associated with their "ATTENDEE" property and send it to 483 the "Organizer". An iCalendar object that maliciously changes the 484 "ATTENDEE" parameters can be constructed by someone other than the 485 real "Attendee" and sent to the "Organizer". 487 PROCEDURAL ALARMS - - An iCalendar object can be created that 488 contains a "VEVENT" and "VTODO" calendar component with "VALARM" 489 calendar components. The "VALARM" calendar component can be of type 490 PROCEDURE and can have an attachment containing some sort of 491 executable program. Implementations that incorporate these types of 492 alarms are subject to any virus or malicious attack that might occur 493 as a result of executing the attachment. 495 ATTACHMENTS - - An iCalendar object can include references to Uniform 496 Resource Locators that can be programmed resources. 498 Implementers and users of this memo should be aware of the network 499 security implications of accepting and parsing such information. In 500 addition, the security considerations observed by implementations of 501 electronic mail systems should be followed for this memo. 503 3.6 Interoperability Considerations 505 This MIME content type is intended to define a common format for 506 conveying calendaring and scheduling information between different 507 systems. It is heavily based on the earlier [VCAL] industry 508 specification. 510 3.7 Applications Which Use This Media Type 512 This content-type is designed for widespread use by Internet 513 calendaring and scheduling applications. In addition, applications in 514 the workflow and document management area might find this content- 515 type applicable. The [ITIP] and [IMIP] Internet protocols directly 516 use this content-type also. Future work on an Internet calendar 517 access protocol will utilize this content-type too. 519 3.8 Additional Information 521 This memo defines this content-type. 523 3.9 Magic Numbers 525 None. 527 3.10 File Extensions 529 The file extension of "ics" is to be used to designate a file 530 containing (an arbitrary set of) calendaring and scheduling 531 information consistent with this MIME content type. 533 The file extension of "ifb" is to be used to designate a file 534 containing free or busy time information consistent with this MIME 535 content type. 537 Macintosh file type codes: The file type code of "iCal" is to be used 538 in Apple MacIntosh operating system environments to designate a file 539 containing calendaring and scheduling information consistent with 540 this MIME media type. 542 The file type code of "iFBf" is to be used in Apple MacIntosh 543 operating system environments to designate a file containing free or 544 busy time information consistent with this MIME media type. 546 3.11 Contact for Further Information: 548 Frank Dawson 549 6544 Battleford Drive 550 Raleigh, NC 27613-3502 551 919-676-9515 (Telephone) 552 919-676-9564 (Data/Facsimile) 553 Frank_Dawson@Lotus.com (Internet Mail) 555 Derik Stenerson 556 One Microsoft Way 557 Redmond, WA 98052-6399 558 425-936-5522 (Telephone) 559 425-936-7329 (Facsimile) 560 deriks@microsoft.com (Internet Mail) 562 3.12 Intended Usage 564 COMMON 566 3.13 Authors/Change Controllers 568 Frank Dawson 569 6544 Battleford Drive 570 Raleigh, NC 27613-3502 571 919-676-9515 (Telephone) 572 919-676-9564 (Data/Facsimile) 573 Frank_Dawson@Lotus.com (Internet Mail) 575 Derik Stenerson 576 One Microsoft Way 577 Redmond, WA 98052-6399 578 425-936-5522 (Telephone) 579 425-936-7329 (Facsimile) 580 deriks@microsoft.com (Internet Mail) 582 4 iCalendar Object Specification 584 The following sections define the details of a Calendaring and 585 Scheduling Core Object Specification. This information is intended to 586 be an integral part of the MIME content type registration. In 587 addition, this information can be used independent of such content 588 registration. In particular, this memo has direct applicability for 589 use as a calendaring and scheduling exchange format in file-, memory- 590 or network-based transport mechanisms. 592 4.1 Content Lines 594 The iCalendar object is organized into individual lines of text, 595 called content lines. Content lines are delimited by a line break, 596 which is a CRLF sequence (US-ASCII decimal 13, followed by US-ASCII 597 decimal 10). 599 Lines of text SHOULD NOT be longer than 75 octets, excluding the line 600 break. Long content lines SHOULD be split into a multiple line 601 representations using a line "folding" technique. That is, a long 602 line can be split between any two characters by inserting a CRLF 603 immediately followed by a single linear white space character (i.e., 604 SPACE, US-ASCII decimal 32 or HTAB, US-ASCII decimal 9). Any sequence 605 of CRLF followed immediately by a single linear white space character 606 is ignored (i.e., removed) when processing the content type. 608 For example the line: 610 DESCRIPTION:This is a long description that exists on a long line. 612 Can be represented as: 614 DESCRIPTION:This is a lo 615 ng description 616 that exists on a long line. 618 The process of moving from this folded multiple line representation 619 to its single line representation is called "unfolding". Unfolding is 620 accomplished by removing the CRLF character and the linear white 621 space character that immediately follows. 623 When parsing a content line, folded lines MUST first be unfolded 624 according to the unfolding procedure described above. When generating 625 a content line, lines longer than 75 octets SHOULD be folded 626 according to the folding procedure described above. 628 The content information associated with an iCalendar object is 629 formatted using a syntax similar to that defined by [MIME DIR]. That 630 is, the content information consists of CRLF-separated content lines. 632 The following notation defines the lines of content in an iCalendar 633 object: 635 contentline = name *(";" param ) ":" value CRLF 636 ; This ABNF is just a general definition for an initial parsing 637 ; of the content line into its property name, parameter list, 638 ; and value string 640 ; When parsing a content line, folded lines MUST first 641 ; be unfolded according to the unfolding procedure 642 ; described above. When generating a content line, lines 643 ; longer than 75 octets SHOULD be folded according to 644 ; the folding procedure described above. 646 name = x-name / iana-token 648 iana-token = 1*(ALPHA / DIGIT / "-") 649 ; iCalendar identifier registered with IANA 650 x-name = "X-" [vendorid "-"] 1*(ALPHA / DIGIT / "-") 651 ; Reservered for experimental use. Not intended for use in 652 ; released products. 654 vendorid = 3*(ALPHA / DIGIT) ;Vendor identification 656 param = param-name "=" param-value 657 *("," param-value) 658 ; Each property defines the specific ABNF for the parameters 659 ; allowed on the property. Refer to specific properties for 660 ; precise parameter ABNF. 662 param-name = iana-token / x-token 664 param-value = paramtext / quoted-string 666 paramtext = *SAFE-CHAR 668 value = *VALUE-CHAR 670 quoted-string = DQUOTE *QSAFE-CHAR DQUOTE 672 NON-US-ASCII = %x80-F8 673 ; Use restricted by charset parameter 674 ; on outer MIME object (UTF-8 preferred) 676 QSAFE-CHAR = WSP / %x21 / %x23-7E / NON-US-ASCII 677 ; Any character except CTLs and DQUOTE 679 SAFE-CHAR = WSP / %x21 / %x23-2B / %x2D-39 / %x3C-7E 680 / NON-US-ASCII 681 ; Any character except CTLs, DQUOTE, ";", ":", "," 683 VALUE-CHAR = WSP / %x21-7E / NON-US-ASCII 684 ; Any textual character 686 CR = %x0D 687 ; carriage return 689 LF = %x0A 690 ; line feed 692 CRLF = CR LF 693 ; Internet standard newline 695 CTL = %x00-08 / %x0A-1F / %x7F 696 ; Controls 698 ALPHA = %x41-5A / %x61-7A ; A-Z / a-z 700 DIGIT = %x30-39 701 ; 0-9 702 DQUOTE = %x22 703 ; Quotation Mark 705 WSP = SPACE / HTAB 707 SPACE = %x20 709 HTAB = %x09 711 The property value component of a content line has a format that is 712 property specific. Refer to the section describing each property for 713 a definition of this format. 715 All names of properties, property parameters, enumerated property 716 values and property parameter values are case-insensitive. However, 717 all other property values are case-sensitive, unless otherwise 718 stated. 720 4.1.1 List and Field Separators 722 Some properties and parameters allow a list of values. Values in a 723 list of values MUST be separated by a COMMA character (US-ASCII 724 decimal 44). There is no significance to the order of values in a 725 list. For those parameter values (such as those that specify URI 726 values) that are specified in quoted-strings, the individual quoted- 727 strings are separated by a COMMA character (US-ASCII decimal 44). 729 Some property values are defined in terms of multiple parts. These 730 structured property values MUST have their value parts separated by a 731 SEMICOLON character (US-ASCII decimal 59). 733 Some properties allow a list of parameters. Each property parameter 734 in a list of property parameters MUST be separated by a SEMICOLON 735 character (US-ASCII decimal 59). 737 Property parameters with values containing a COLON, a SEMICOLON or a 738 COMMA character MUST be placed in quoted text. 740 For example, in the following properties a SEMICOLON is used to 741 separate property parameters from each other, and a COMMA is used to 742 separate property values in a value list. 744 ATTENDEE;RSVP=TRUE;ROLE=REQ-PARTICIPANT:MAILTO: 745 jsmith@host.com 747 RDATE;VALUE=DATE:19970304,19970504,19970704,19970904 749 4.1.2 Multiple Values 751 Some properties defined in the iCalendar object can have multiple 752 values. The general rule for encoding multi-valued items is to simply 753 create a new content line for each value, including the property 754 name. However, it should be noted that some properties support 755 encoding multiple values in a single property by separating the 756 values with a COMMA character (US-ASCII decimal 44). Individual 757 property definitions should be consulted for determining whether a 758 specific property allows multiple values and in which of these two 759 forms. 761 4.1.3 Binary Content 763 Binary content information in an iCalendar object SHOULD be 764 referenced using a URI within a property value. That is the binary 765 content information SHOULD be placed in an external MIME entity that 766 can be referenced by a URI from within the iCalendar object. In 767 applications where this is not feasible, binary content information 768 can be included within an iCalendar object, but only after first 769 encoding it into text using the "BASE64" encoding method defined in 770 [RFC 2045]. Inline binary contact SHOULD only be used in applications 771 whose special circumstances demand that an iCalendar object be 772 expressed as a single entity. A property containing inline binary 773 content information MUST specify the "ENCODING" property parameter. 774 Binary content information placed external to the iCalendar object 775 MUST be referenced by a uniform resource identifier (URI). 777 The following example specifies an "ATTACH" property that references 778 an attachment external to the iCalendar object with a URI reference: 780 ATTACH:http://xyz.com/public/quarterly-report.doc 782 The following example specifies an "ATTACH" property with inline 783 binary encoded content information: 785 ATTACH;FMTTYPE=image/basic;ENCODING=BASE64;VALUE=BINARY: 786 MIICajCCAdOgAwIBAgICBEUwDQYJKoZIhvcNAQEEBQAwdzELMAkGA1U 787 EBhMCVVMxLDAqBgNVBAoTI05ldHNjYXBlIENvbW11bmljYXRpb25zIE 788 <...remainder of "BASE64" encoded binary data...> 790 4.1.4 Character Set 792 There is not a property parameter to declare the character set used 793 in a property value. The default character set for an iCalendar 794 object is UTF-8 as defined in [RFC 2279]. 796 The "charset" Content-Type parameter can be used in MIME transports 797 to specify any other IANA registered character set. 799 4.2 Property Parameters 801 A property can have attributes associated with it. These "property 802 parameters" contain meta-information about the property or the 803 property value. Property parameters are provided to specify such 804 information as the location of an alternate text representation for a 805 property value, the language of a text property value, the data type 806 of the property value and other attributes. 808 Property parameter values that contain the COLON (US-ASCII decimal 809 58), SEMICOLON (US-ASCII decimal 59) or COMMA (US-ASCII decimal 44) 810 character separators MUST be specified as quoted-string text values. 811 Property parameter values MUST NOT contain the DOUBLE-QUOTE (US-ASCII 812 decimal 22) character. The DOUBLE-QUOTE (US-ASCII decimal 22) 813 character is used as a delimiter for parameter values that contain 814 restricted characters or URI text. For example: 816 DESCRIPTION;ALTREP="http://www.wiz.org":The Fall'98 Wild Wizards 817 Conference - - Las Vegas, NV, USA 819 Property parameter values that are not in quoted strings are case 820 insensitive. 822 The general property parameters defined by this memo are defined by 823 the following notation: 825 parameter = altrepparam ; Alternate text representation 826 / cnparam ; Common name 827 / cutypeparam ; Calendar user type 828 / delfromparam ; Delegator 829 / deltoparam ; Delegatee 830 / dirparam ; Directory entry 831 / encodingparam ; Inline encoding 832 / fmttypeparam ; Format type 833 / fbtypeparam ; Free/busy time type 834 / languageparam ; Language for text 835 / memberparam ; Group or list membership 836 / partstatparam ; Participation status 837 / rangeparam ; Recurrence identifier range 838 / trigrelparam ; Alarm trigger relationship 839 / reltypeparam ; Relationship type 840 / roleparam ; Participation role 841 / rsvpparam ; RSVP expectation 842 / sentbyparam ; Sent by 843 / tzidparam ; Reference to time zone object 844 / valuetypeparam ; Property value data type 845 / ianaparam 846 ; Some other IANA registered iCalendar parameter. 847 / xparam 848 ; A non-standard, experimental parameter. 850 ianaparam = iana-token "=" param-value *("," param-value) 852 xparam =x-name "=" param-value *("," param-value) 854 4.2.1 Alternate Text Representation 856 Parameter Name: ALTREP 858 Purpose: To specify an alternate text representation for the property 859 value. 861 Format Definition: The property parameter is defined by the following 862 notation: 864 altrepparam = "ALTREP" "=" DQUOTE uri DQUOTE 866 Description: The parameter specifies a URI that points to an 867 alternate representation for a textual property value. A property 868 specifying this parameter MUST also include a value that reflects the 869 default representation of the text value. The individual URI 870 parameter values MUST each be specified in a quoted-string. 872 Example: 874 DESCRIPTION;ALTREP="CID:":Project 875 XYZ Review Meeting will include the following agenda items: (a) 876 Market Overview, (b) Finances, (c) Project Management 878 The "ALTREP" property parameter value might point to a "text/html" 879 content portion. 881 Content-Type:text/html 882 Content-Id: 884 885

Project XYZ Review Meeting will include the following 886 agenda items:

  1. Market 887 Overview
  2. Finances
  3. Project Management

888 890 4.2.2 Common Name 892 Parameter Name: CN 894 Purpose: To specify the common name to be associated with the 895 calendar user specified by the property. 897 Format Definition: The property parameter is defined by the following 898 notation: 900 cnparam = "CN" "=" param-value 902 Description: This parameter can be specified on properties with a 903 CAL-ADDRESS value type. The parameter specifies the common name to be 904 associated with the calendar user specified by the property. The 905 parameter value is text. The parameter value can be used for display 906 text to be associated with the calendar address specified by the 907 property. 909 Example: 911 ORGANIZER;CN="John Smith":MAILTO:jsmith@host.com 913 4.2.3 Calendar User Type 915 Parameter Name: CUTYPE 916 Purpose: To specify the type of calendar user specified by the 917 property. 919 Format Definition: The property parameter is defined by the following 920 notation: 922 cutypeparam = "CUTYPE" "=" 923 ("INDIVIDUAL" ; An individual 924 / "GROUP" ; A group of individuals 925 / "RESOURCE" ; A physical resource 926 / "ROOM" ; A room resource 927 / "UNKNOWN" ; Otherwise not known 928 / x-name ; Experimental type 929 / iana-token) ; Other IANA registered 930 ; type 931 ; Default is INDIVIDUAL 933 Description: This parameter can be specified on properties with a 934 CAL-ADDRESS value type. The parameter identifies the type of calendar 935 user specified by the property. If not specified on a property that 936 allows this parameter, the default is INDIVIDUAL. 938 Example: 940 ATTENDEE;CUTYPE=GROUP:MAILTO:ietf-calsch@imc.org 942 4.2.4 Delegators 944 Parameter Name: DELEGATED-FROM 946 Purpose: To specify the calendar users that have delegated their 947 participation to the calendar user specified by the property. 949 Format Definition: The property parameter is defined by the following 950 notation: 952 delfromparam = "DELEGATED-FROM" "=" DQUOTE cal-address DQUOTE 953 *("," DQUOTE cal-address DQUOTE) 955 Description: This parameter can be specified on properties with a 956 CAL-ADDRESS value type. This parameter can be specified on a property 957 that has a value type of calendar address. This parameter specifies 958 those calendar uses that have delegated their participation in a 959 group scheduled event or to-do to the calendar user specified by the 960 property. The value MUST be a MAILTO URI as defined in [RFC 1738]. 961 The individual calendar address parameter values MUST each be 962 specified in a quoted-string. 964 Example: 966 ATTENDEE;DELEGATED-FROM="MAILTO:jsmith@host.com":MAILTO: 967 jdoe@host.com 968 4.2.5 Delegatees 970 Parameter Name: DELEGATED-TO 972 Purpose: To specify the calendar users to whom the calendar user 973 specified by the property has delegated participation. 975 Format Definition: The property parameter is defined by the following 976 notation: 978 deltoparam = "DELEGATED-TO" "=" DQUOTE cal-address DQUOTE 979 *("," DQUOTE cal-address DQUOTE) 981 Description: This parameter can be specified on properties with a 982 CAL-ADDRESS value type. This parameter specifies those calendar users 983 whom have been delegated participation in a group scheduled event or 984 to-do by the calendar user specified by the property. The value MUST 985 be a MAILTO URI as defined in [RFC 1738]. The individual calendar 986 address parameter values MUST each be specified in a quoted-string. 988 Example: 990 ATTENDEE;DELEGATED-TO="MAILTO:jdoe@host.com","MAILTO:jqpublic@ 991 host.com":MAILTO:jsmith@host.com 993 4.2.6 Directory Entry Reference 995 Parameter Name: DIR 997 Purpose: To specify reference to a directory entry associated with 998 the calendar user specified by the property. 1000 Format Definition: The property parameter is defined by the following 1001 notation: 1003 dirparam = "DIR" "=" DQUOTE uri DQUOTE 1005 Description: This parameter can be specified on properties with a 1006 CAL-ADDRESS value type. The parameter specifies a reference to the 1007 directory entry associated with the calendar user specified by the 1008 property. The parameter value is a URI. The individual URI parameter 1009 values MUST each be specified in a quoted-string. 1011 Example: 1013 ORGANIZER;DIR="ldap://host.com:6666/o=eDABC%20Industries,c=3DUS?? 1014 (cn=3DBJim%20Dolittle)":MAILTO:jimdo@host1.com 1016 4.2.7 Inline Encoding 1018 Parameter Name: ENCODING 1020 Purpose: To specify an alternate inline encoding for the property 1021 value. 1023 Format Definition: The property parameter is defined by the following 1024 notation: 1026 encodingparam = "ENCODING" "=" 1027 ("8BIT" 1028 ; "8bit" text encoding is defined in [RFC 2045] 1029 / "BASE64" 1030 ; "BASE64" binary encoding format is defined in [RFC 2045] 1031 / iana-token 1032 ; Some other IANA registered iCalendar encoding type 1033 / x-name) 1034 ; A non-standard, experimental encoding type 1036 Description: The property parameter identifies the inline encoding 1037 used in a property value. The default encoding is "8BIT", 1038 corresponding to a property value consisting of text. The "BASE64" 1039 encoding type corresponds to a property value encoded using the 1040 "BASE64" encoding defined in [RFC 2045]. 1042 If the value type parameter is ";VALUE=BINARY", then the inline 1043 encoding parameter MUST be specified with the value 1044 ";ENCODING=BASE64". 1046 Example: 1048 ATTACH;FMTYPE=IMAGE/JPEG;ENCODING=BASE64;VALUE=BINARY:MIICajC 1049 CAdOgAwIBAgICBEUwDQYJKoZIhvcNAQEEBQAwdzELMAkGA1UEBhMCVVMxLDA 1050 qBgNVBAoTI05ldHNjYXBlIENvbW11bmljYXRpb25zIENvcnBvcmF0aW9uMRw 1051 <...remainder of "BASE64" encoded binary data...> 1053 4.2.8 Format Type 1055 Parameter Name: FMTTYPE 1057 Purpose: To specify the content type of a referenced object. 1059 Format Definition: The property parameter is defined by the following 1060 notation: 1062 fmttypeparam = "FMTTYPE" "=" iana-token 1063 ; A IANA registered content type 1064 / x-name 1065 ; A non-standard content type 1067 Description: This parameter can be specified on properties that are 1068 used to reference an object. The parameter specifies the content type 1069 of the referenced object. For example, on the "ATTACH" property, a 1070 FTP type URI value does not, by itself, necessarily convey the type 1071 of content associated with the resource. The parameter value MUST be 1072 the TEXT for either an IANA registered content type or a non-standard 1073 content type. 1075 Example: 1077 ATTACH;FMTTYPE=application/binary:ftp://domain.com/pub/docs/ 1078 agenda.doc 1080 4.2.9 Free/Busy Time Type 1082 Parameter Name: FBTYPE 1084 Purpose: To specify the free or busy time type. 1086 Format Definition: The property parameter is defined by the following 1087 notation: 1089 fbtypeparam = "FBTYPE" "=" ("FREE" / "BUSY" 1090 / "BUSY-UNAVAILABLE" / "BUSY-TENTATIVE" 1091 / x-name 1092 ; Some experimental iCalendar data type. 1093 / iana-token) 1094 ; Some other IANA registered iCalendar data type. 1096 Description: The parameter specifies the free or busy time type. The 1097 value FREE indicates that the time interval is free for scheduling. 1098 The value BUSY indicates that the time interval is busy because one 1099 or more events have been scheduled for that interval. The value BUSY- 1100 UNAVAILABLE indicates that the time interval is busy and that the 1101 interval can not be scheduled. The value BUSY-TENTATIVE indicates 1102 that the time interval is busy because one or more events have been 1103 tentatively scheduled for that interval. If not specified on a 1104 property that allows this parameter, the default is BUSY. 1106 Example: The following is an example of this parameter on a FREEBUSY 1107 property. 1109 FREEBUSY;FBTYPE=BUSY:19980415T133000Z/19980415T170000Z 1111 4.2.10 Language 1113 Parameter Name: LANGUAGE 1115 Purpose: To specify the language for text values in a property or 1116 property parameter. 1118 Format Definition: The property parameter is defined by the following 1119 notation: 1121 languageparam = "LANGUAGE" "=" language 1123 language = 1125 Description: This parameter can be specified on properties with a 1126 text value type. The parameter identifies the language of the text in 1127 the property or property parameter value. The value of the "language" 1128 property parameter is that defined in [RFC 1766]. 1130 For transport in a MIME entity, the Content-Language header field can 1131 be used to set the default language for the entire body part. 1132 Otherwise, no default language is assumed. 1134 Example: 1136 SUMMARY;LANGUAGE=us-EN:Company Holiday Party 1138 LOCATION;LANGUAGE=en:Germany 1139 LOCATION;LANGUAGE=no:Tyskland 1141 The following example makes use of the Quoted-Printable encoding in 1142 order to represent non-ASCII characters. 1144 LOCATION;LANGUAGE=da:K=F8benhavn 1145 LOCATION;LANGUAGE=en:Copenhagen 1147 4.2.11 Group or List Membership 1149 Parameter Name: MEMBER 1151 Purpose: To specify the group or list membership of the calendar user 1152 specified by the property. 1154 Format Definition: The property parameter is defined by the following 1155 notation: 1157 memberparam = "MEMBER" "=" DQUOTE cal-address DQUOTE 1158 *("," DQUOTE cal-address DQUOTE) 1160 Description: This parameter can be specified on properties with a 1161 CAL-ADDRESS value type. The parameter identifies the groups or list 1162 membership for the calendar user specified by the property. The 1163 parameter value either a single calendar address in a quoted-string 1164 or a COMMA character (US-ASCII decimal 44) list of calendar 1165 addresses, each in a quoted-string. The individual calendar address 1166 parameter values MUST each be specified in a quoted-string. 1168 Example: 1170 ATTENDEE;MEMBER="MAILTO:ietf-calsch@imc.org":MAILTO:jsmith@host.com 1172 ATTENDEE;MEMBER="MAILTO:projectA@host.com","MAILTO:projectB@host. 1173 com":MAILTO:janedoe@host.com 1175 4.2.12 Participation Status 1177 Parameter Name: PARTSTAT 1179 Purpose: To specify the participation status for the calendar user 1180 specified by the property. 1182 Format Definition: The property parameter is defined by the following 1183 notation: 1185 partstatparam = "PARTSTAT" "=" 1186 ("NEEDS-ACTION" ; Event needs action 1187 / "ACCEPTED" ; Event accepted 1188 / "DECLINED" ; Event declined 1189 / "TENTATIVE" ; Event tentatively 1190 ; accepted 1191 / "DELEGATED" ; Event delegated 1192 / x-name ; Experimental status 1193 / iana-token) ; Other IANA registered 1194 ; status 1195 ; These are the participation statuses for a "VEVENT". Default is 1196 ; NEEDS-ACTION 1198 partstatparam /= "PARTSTAT" "=" 1199 ("NEEDS-ACTION" ; To-do needs action 1200 / "ACCEPTED" ; To-do accepted 1201 / "DECLINED" ; To-do declined 1202 / "TENTATIVE" ; To-do tentatively 1203 ; accepted 1204 / "DELEGATED" ; To-do delegated 1205 / "COMPLETED" ; To-do completed. 1206 ; COMPLETED property has 1207 ;date/time completed. 1208 / "IN-PROCESS" ; To-do in process of 1209 ; being completed 1210 / x-name ; Experimental status 1211 / iana-token) ; Other IANA registered 1212 ; status 1213 ; These are the participation statuses for a "VTODO". Default is 1214 ; NEEDS-ACTION 1216 partstatparam /= "PARTSTAT" "=" 1217 ("NEEDS-ACTION" ; Journal needs action 1218 / "ACCEPTED" ; Journal accepted 1219 / "DECLINED" ; Journal declined 1220 / x-name ; Experimental status 1221 / iana-token) ; Other IANA registered 1222 ; status 1223 ; These are the participation statuses for a "VJOURNAL". Default is 1224 ; NEEDS-ACTION 1226 Description: This parameter can be specified on properties with a 1227 CAL-ADDRESS value type. The parameter identifies the participation 1228 status for the calendar user specified by the property value. The 1229 parameter values differ depending on whether they are associated with 1230 a group scheduled "VEVENT", "VTODO" or "VJOURNAL". The values MUST 1231 match one of the values allowed for the given calendar component. If 1232 not specified on a property that allows this parameter, the default 1233 value is NEEDS-ACTION. 1235 Example: 1237 ATTENDEE;PARTSTAT=DECLINED:MAILTO:jsmith@host.com 1238 4.2.13 Recurrence Identifier Range 1240 Parameter Name: RANGE 1242 Purpose: To specify the effective range of recurrence instances from 1243 the instance specified by the recurrence identifier specified by the 1244 property. 1246 Format Definition: The property parameter is defined by the following 1247 notation: 1249 rangeparam = "RANGE" "=" ("THISANDPRIOR" 1250 ; To specify all instances prior to the recurrence identifier 1251 / "THISANDFUTURE") 1252 ; To specify the instance specified by the recurrence identifier 1253 ; and all subsequent recurrence instances 1255 Description: The parameter can be specified on a property that 1256 specifies a recurrence identifier. The parameter specifies the 1257 effective range of recurrence instances that is specified by the 1258 property. The effective range is from the recurrence identified 1259 specified by the property. If this parameter is not specified an 1260 allowed property, then the default range is the single instance 1261 specified by the recurrence identifier value of the property. The 1262 parameter value can be "THISANDPRIOR" to indicate a range defined by 1263 the recurrence identified value of the property and all prior 1264 instances. The parameter value can also be "THISANDFUTURE" to 1265 indicate a range defined by the recurrence identifier and all 1266 subsequent instances. 1268 Example: 1270 RECURRENCE-ID;RANGE=THISANDPRIOR:19980401T133000Z 1272 4.2.14 Alarm Trigger Relationship 1274 Parameter Name: RELATED 1276 Purpose: To specify the relationship of the alarm trigger with 1277 respect to the start or end of the calendar component. 1279 Format Definition: The property parameter is defined by the following 1280 notation: 1282 trigrelparam = "RELATED" "=" 1283 ("START" ; Trigger off of start 1284 / "END") ; Trigger off of end 1286 Description: The parameter can be specified on properties that 1287 specify an alarm trigger with a DURATION value type. The parameter 1288 specifies whether the alarm will trigger relative to the start or end 1289 of the calendar component. The parameter value START will set the 1290 alarm to trigger off the start of the calendar component; the 1291 parameter value END will set the alarm to trigger off the end of the 1292 calendar component. If the parameter is not specified on an allowable 1293 property, then the default is START. 1295 Example: 1297 TRIGGER;RELATED=END:PT5M 1299 4.2.15 Relationship Type 1301 Parameter Name: RELTYPE 1303 Purpose: To specify the type of hierarchical relationship associated 1304 with the calendar component specified by the property. 1306 Format Definition: The property parameter is defined by the following 1307 notation: 1309 reltypeparam = "RELTYPE" "=" 1310 ("PARENT" ; Parent relationship. Default. 1311 / "CHILD" ; Child relationship 1312 / "SIBLING ; Sibling relationship 1313 / iana-token ; Some other IANA registered 1314 ; iCalendar relationship type 1315 / x-name) ; A non-standard, experimental 1316 ; relationship type 1318 Description: This parameter can be specified on a property that 1319 references another related calendar. The parameter specifies the 1320 hierarchical relationship type of the calendar component referenced 1321 by the property. The parameter value can be PARENT, to indicate that 1322 the referenced calendar component is a superior of calendar 1323 component; CHILD to indicate that the referenced calendar component 1324 is a subordinate of the calendar component; SIBLING to indicate that 1325 the referenced calendar component is a peer of the calendar 1326 component. If this parameter is not specified on an allowable 1327 property, the default relationship type is PARENT. 1329 Example: 1331 RELATED-TO;RELTYPE=SIBLING:<19960401-080045-4000F192713@host.com> 1333 4.2.16 Participation Role 1335 Parameter Name: ROLE 1337 Purpose: To specify the participation role for the calendar user 1338 specified by the property. 1340 Format Definition: The property parameter is defined by the following 1341 notation: 1343 roleparam = "ROLE" "=" 1344 ("CHAIR" ; Indicates chair of the 1345 ; calendar entity 1346 / "REQ-PARTICIPANT" ; Indicates a participant whose 1347 ; participation is required 1348 / "OPT-PARTICIPANT" ; Indicates a participant whose 1349 ; participation is optional 1350 / "NON-PARTICIPANT" ; Indicates a participant who is 1351 ; copied for information 1352 ; purposes only 1353 / x-name ; Experimental role 1354 / iana-token) ; Other IANA role 1355 ; Default is REQ-PARTICIPANT 1357 Description: This parameter can be specified on properties with a 1358 CAL-ADDRESS value type. The parameter specifies the participation 1359 role for the calendar user specified by the property in the group 1360 schedule calendar component. If not specified on a property that 1361 allows this parameter, the default value is REQ-PARTICIPANT. 1363 Example: 1365 ATTENDEE;ROLE=CHAIR:MAILTO:mrbig@host.com 1367 4.2.17 RSVP Expectation 1369 Parameter Name: RSVP 1371 Purpose: To specify whether there is an expectation of a favor of a 1372 reply from the calendar user specified by the property value. 1374 Format Definition: The property parameter is defined by the following 1375 notation: 1377 rsvpparam = "RSVP" "=" ("TRUE" / "FALSE") 1378 ; Default is FALSE 1380 Description: This parameter can be specified on properties with a 1381 CAL-ADDRESS value type. The parameter identifies the expectation of a 1382 reply from the calendar user specified by the property value. This 1383 parameter is used by the "Organizer" to request a participation 1384 status reply from an "Attendee" of a group scheduled event or to-do. 1385 If not specified on a property that allows this parameter, the 1386 default value is FALSE. 1388 Example: 1390 ATTENDEE;RSVP=TRUE:MAILTO:jsmith@host.com 1392 4.2.18 Sent By 1394 Parameter Name: SENT-BY 1396 Purpose: To specify the calendar user that is acting on behalf of the 1397 calendar user specified by the property. 1399 Format Definition: The property parameter is defined by the following 1400 notation: 1402 sentbyparam = "SENT-BY" "=" DQUOTE cal-address DQUOTE 1404 Description: This parameter can be specified on properties with a 1405 CAL-ADDRESS value type. The parameter specifies the calendar user 1406 that is acting on behalf of the calendar user specified by the 1407 property. The parameter value MUST be a MAILTO URI as defined in [RFC 1408 1738]. The individual calendar address parameter values MUST each be 1409 specified in a quoted-string. 1411 Example: 1413 ORGANIZER;SENT-BY:"MAILTO:sray@host.com":MAILTO:jsmith@host.com 1415 4.2.19 Time Zone Identifier 1417 Parameter Name: TZID 1419 Purpose: To specify the identifier for the time zone definition for a 1420 time component in the property value. 1422 Format Definition: This property parameter is defined by the 1423 following notation: 1425 tzidparam = "TZID" "=" [tzidprefix] paramtext CRLF 1427 tzidprefix = "/" 1429 Description: The parameter MUST be specified on the "DTSTART", 1430 "DTEND", "DUE", "EXDATE" and "RDATE" properties when either a DATE- 1431 TIME or TIME value type is specified and when the value is not either 1432 a UTC or a "floating" time. Refer to the DATE-TIME or TIME value type 1433 definition for a description of UTC and "floating time" formats. This 1434 property parameter specifies a text value which uniquely identifies 1435 the "VTIMEZONE" calendar component to be used when evaluating the 1436 time portion of the property. The value of the TZID property 1437 parameter will be equal to the value of the TZID property for the 1438 matching time zone definition. An individual "VTIMEZONE" calendar 1439 component MUST be specified for each unique "TZID" parameter value 1440 specified in the iCalendar object. 1442 The parameter MUST be specified on properties with a DATE-TIME value 1443 if the DATE-TIME is not either a UTC or a "floating" time. 1445 The presence of the SOLIDUS character (US-ASCII decimal 47) as a 1446 prefix, indicates that this TZID represents a unique ID in a globally 1447 defined time zone registry (when such registry is defined). 1449 Note: This document does not define a naming convention for time 1450 zone identifiers. Implementers may want to use the naming 1451 conventions defined in existing time zone specifications such as 1452 the public-domain Olson database [TZ]. The specification of 1453 globally unique time zone identifiers is not addressed by this 1454 document and is left for future study. 1456 The following are examples of this property parameter: 1458 DTSTART;TZID=US-Eastern:19980119T020000 1460 DTEND;TZID=US-Eastern:19980119T030000 1462 The TZID property parameter MUST NOT be applied to DATE-TIME or TIME 1463 properties whose time values are specified in UTC. 1465 The use of local time in a DATE-TIME or TIME value without the TZID 1466 property parameter is to be interpreted as a local time value, 1467 regardless of the existence of "VTIMEZONE" calendar components in the 1468 iCalendar object. 1470 For more information see the sections on the data types DATE-TIME and 1471 TIME. 1473 4.2.20 Value Data Types 1475 Parameter Name: VALUE 1477 Purpose: To explicitly specify the data type format for a property 1478 value. 1480 Format Definition: The "VALUE" property parameter is defined by the 1481 following notation: 1483 valuetypeparam = "VALUE" "=" valuetype 1485 valuetype = ("BINARY" 1486 / "BOOLEAN" 1487 / "CAL-ADDRESS" 1488 / "DATE" 1489 / "DATE-TIME" 1490 / "DURATION" 1491 / "FLOAT" 1492 / "INTEGER" 1493 / "PERIOD" 1494 / "RECUR" 1495 / "TEXT" 1496 / "TIME" 1497 / "URI" 1498 / "UTC-OFFSET" 1499 / x-name 1500 ; Some experimental iCalendar data type. 1501 / iana-token) 1502 ; Some other IANA registered iCalendar data type. 1504 Description: The parameter specifies the data type and format of the 1505 property value. The property values MUST be of a single value type. 1507 For example, a "RDATE" property cannot have a combination of DATE- 1508 TIME and TIME value types. 1510 If the property's value is the default value type, then this 1511 parameter need not be specified. However, if the property's default 1512 value type is overridden by some other allowable value type, then 1513 this parameter MUST be specified. 1515 4.3 Property Value Data Types 1517 The properties in an iCalendar object are strongly typed. The 1518 definition of each property restricts the value to be one of the 1519 value data types, or simply value types, defined in this section. The 1520 value type for a property will either be specified implicitly as the 1521 default value type or will be explicitly specified with the "VALUE" 1522 parameter. If the value type of a property is one of the alternate 1523 valid types, then it MUST be explicitly specified with the "VALUE" 1524 parameter. 1526 4.3.1 Binary 1528 Value Name: BINARY 1530 Purpose: This value type is used to identify properties that contain 1531 a character encoding of inline binary data. For example, an inline 1532 attachment of an object code might be included in an iCalendar 1533 object. 1535 Formal Definition: The value type is defined by the following 1536 notation: 1538 binary = *(4b-char) [b-end] 1539 ; A "BASE64" encoded character string, as defined by [RFC 2045]. 1541 b-end = (2b-char "==") / (3b-char "=") 1543 b-char = ALPHA / DIGIT / "+" / "/" 1545 Description: Property values with this value type MUST also include 1546 the inline encoding parameter sequence of ";ENCODING=BASE64". That 1547 is, all inline binary data MUST first be character encoded using the 1548 "BASE64" encoding method defined in [RFC 2045]. No additional content 1549 value encoding (i.e., BACKSLASH character encoding) is defined for 1550 this value type. 1552 Example: The following is an abridged example of a "BASE64" encoded 1553 binary value data. 1555 ATTACH;VALUE=BINARY;ENCODING=BASE64:MIICajCCAdOgAwIBAgICBEUwDQY 1556 JKoZIhvcNAQEEBQAwdzELMAkGA1UEBhMCVVMxLDAqBgNVBAoTI05ldHNjYXBlI 1557 ENvbW11bmljYXRpb25zIENvcnBvcmF0aW9uMRwwGgYDVQQLExNJbmZv 1558 <...remainder of "BASE64" encoded binary data...> 1559 4.3.2 Boolean 1561 Value Name: BOOLEAN 1563 Purpose: This value type is used to identify properties that contain 1564 either a "TRUE" or "FALSE" Boolean value. 1566 Formal Definition: The value type is defined by the following 1567 notation: 1569 boolean = "TRUE" / "FALSE" 1571 Description: These values are case insensitive text. No additional 1572 content value encoding (i.e., BACKSLASH character encoding) is 1573 defined for this value type. 1575 Example: The following is an example of a hypothetical property that 1576 has a BOOLEAN value type: 1578 GIBBERISH:TRUE 1580 4.3.3 Calendar User Address 1582 Value Name: CAL-ADDRESS 1584 Purpose: This value type is used to identify properties that contain 1585 a calendar user address. 1587 Formal Definition: The value type is as defined by the following 1588 notation: 1590 cal-address = uri 1592 Description: The value is a URI as defined by [RFC 1738] or any other 1593 IANA registered form for a URI. When used to address an Internet 1594 email transport address for a calendar user, the value MUST be a 1595 MAILTO URI, as defined by [RFC 1738]. No additional content value 1596 encoding (i.e., BACKSLASH character encoding) is defined for this 1597 value type. 1599 Example: 1601 ATTENDEE:MAILTO:jane_doe@host.com 1603 4.3.4 Date 1605 Value Name: DATE 1607 Purpose: This value type is used to identify values that contain a 1608 calendar date. 1610 Formal Definition: The value type is defined by the following 1611 notation: 1613 date = date-value 1615 date-value = date-fullyear date-month date-mday 1616 date-fullyear = 4DIGIT 1617 date-month = 2DIGIT ;01-12 1618 date-mday = 2DIGIT ;01-28, 01-29, 01-30, 01-31 1619 ;based on month/year 1621 Description: If the property permits, multiple "date" values are 1622 specified as a COMMA character (US-ASCII decimal 44) separated list 1623 of values. The format for the value type is expressed as the [ISO 1624 8601] complete representation, basic format for a calendar date. The 1625 textual format specifies a four-digit year, two-digit month, and two- 1626 digit day of the month. There are no separator characters between the 1627 year, month and day component text. 1629 No additional content value encoding (i.e., BACKSLASH character 1630 encoding) is defined for this value type. 1632 Example: The following represents July 14, 1997: 1634 19970714 1636 4.3.5 Date-Time 1638 Value Name: DATE-TIME 1640 Purpose: This value type is used to identify values that specify a 1641 precise calendar date and time of day. 1643 Formal Definition: The value type is defined by the following 1644 notation: 1646 date-time = date "T" time ;As specified in the date and time 1647 ;value definitions 1649 Description: If the property permits, multiple "date-time" values are 1650 specified as a COMMA character (US-ASCII decimal 44) separated list 1651 of values. No additional content value encoding (i.e., BACKSLASH 1652 character encoding) is defined for this value type. 1654 The "DATE-TIME" data type is used to identify values that contain a 1655 precise calendar date and time of day. The format is based on the 1656 [ISO 8601] complete representation, basic format for a calendar date 1657 and time of day. The text format is a concatenation of the "date", 1658 followed by the LATIN CAPITAL LETTER T character (US-ASCII decimal 1659 84) time designator, followed by the "time" format. 1661 The "DATE-TIME" data type expresses time values in three forms: 1663 The form of date and time with UTC offset MUST NOT be used. For 1664 example, the following is not valid for a date-time value: 1666 DTSTART:19980119T230000-0800 ;Invalid time format 1667 FORM #1: DATE WITH LOCAL TIME 1669 The date with local time form is simply a date-time value that does 1670 not contain the UTC designator nor does it reference a time zone. For 1671 example, the following represents Janurary 18, 1998, at 11 PM: 1673 DTSTART:19980118T230000 1675 Date-time values of this type are said to be "floating" and are not 1676 bound to any time zone in particular. They are used to represent the 1677 same hour, minute, and second value regardless of which time zone is 1678 currently being observed. For example, an event can be defined that 1679 indicates that an individual will be busy from 11:00 AM to 1:00 PM 1680 every day, no matter which time zone the person is in. In these 1681 cases, a local time can be specified. The recipient of an iCalendar 1682 object with a property value consisting of a local time, without any 1683 relative time zone information, SHOULD interpret the value as being 1684 fixed to whatever time zone the ATTENDEE is in at any given moment. 1685 This means that two ATTENDEEs, in different time zones, receiving the 1686 same event definition as a floating time, may be participating in the 1687 event at different actual times. Floating time SHOULD only be used 1688 where that is the reasonable behavior. 1690 In most cases, a fixed time is desired. To properly communicate a 1691 fixed time in a property value, either UTC time or local time with 1692 time zone reference MUST be specified. 1694 The use of local time in a DATE-TIME value without the TZID property 1695 parameter is to be interpreted as floating time, regardless of the 1696 existence of "VTIMEZONE" calendar components in the iCalendar object. 1698 FORM #2: DATE WITH UTC TIME 1700 The date with UTC time, or absolute time, is identified by a LATIN 1701 CAPITAL LETTER Z suffix character (US-ASCII decimal 90), the UTC 1702 designator, appended to the time value. For example, the following 1703 represents January 19, 1998, at 0700 UTC: 1705 DTSTART:19980119T070000Z 1707 The TZID property parameter MUST NOT be applied to DATE-TIME 1708 properties whose time values are specified in UTC. 1710 FORM #3: DATE WITH LOCAL TIME AND TIME ZONE REFERENCE 1712 The date and local time with reference to time zone information is 1713 identified by the use the TZID property parameter to reference the 1714 appropriate time zone definition. TZID is discussed in detail in the 1715 section on Time Zone. For example, the following represents 2 AM in 1716 New York on Janurary 19, 1998: 1718 DTSTART;TZID=US-Eastern:19980119T020000 1719 Example: The following represents July 14, 1997, at 1:30 PM in New 1720 York City in each of the three time formats, using the "DTSTART" 1721 property. 1723 DTSTART:19970714T133000 ;Local time 1724 DTSTART:19970714T173000Z ;UTC time 1725 DTSTART;TZID=US-Eastern:19970714T133000 ;Local time and time 1726 ; zone reference 1728 A time value MUST ONLY specify 60 seconds when specifying the 1729 periodic "leap second" in the time value. For example: 1731 COMPLETED:19970630T235960Z 1733 4.3.6 Duration 1735 Value Name: DURATION 1737 Purpose: This value type is used to identify properties that contain 1738 a duration of time. 1740 Formal Definition: The value type is defined by the following 1741 notation: 1743 dur-value = (["+"] / "-") "P" (dur-date / dur-time / dur-week) 1745 dur-date = dur-day [dur-time] 1746 dur-time = "T" (dur-hour / dur-minute / dur-second) 1747 dur-week = 1*DIGIT "W" 1748 dur-hour = 1*DIGIT "H" [dur-minute] 1749 dur-minute = 1*DIGIT "M" [dur-second] 1750 dur-second = 1*DIGIT "S" 1751 dur-day = 1*DIGIT "D" 1753 Description: If the property permits, multiple "duration" values are 1754 specified by a COMMA character (US-ASCII decimal 44) separated list 1755 of values. The format is expressed as the [ISO 8601] basic format for 1756 the duration of time. The format can represent durations in terms of 1757 weeks, days, hours, minutes, and seconds. 1759 No additional content value encoding (i.e., BACKSLASH character 1760 encoding) are defined for this value type. 1762 Example: A duration of 15 days, 5 hours and 20 seconds would be: 1764 P15DT5H0M20S 1766 A duration of 7 weeks would be: 1768 P7W 1770 4.3.7 Float 1772 Value Name: FLOAT 1773 Purpose: This value type is used to identify properties that contain 1774 a real number value. 1776 Formal Definition: The value type is defined by the following 1777 notation: 1779 float = (["+"] / "-") 1*DIGIT ["." 1*DIGIT] 1781 Description: If the property permits, multiple "float" values are 1782 specified by a COMMA character (US-ASCII decimal 44) separated list 1783 of values. 1785 No additional content value encoding (i.e., BACKSLASH character 1786 encoding) is defined for this value type. 1788 Example: 1790 1000000.0000001 1791 1.333 1792 -3.14 1794 4.3.8 Integer 1796 Value Name:INTEGER 1798 Purpose: This value type is used to identify properties that contain 1799 a signed integer value. 1801 Formal Definition: The value type is defined by the following 1802 notation: 1804 integer = (["+"] / "-") 1*DIGIT 1806 Description: If the property permits, multiple "integer" values are 1807 specified by a COMMA character (US-ASCII decimal 44) separated list 1808 of values. The valid range for "integer" is -2147483648 to 1809 2147483647. If the sign is not specified, then the value is assumed 1810 to be positive. 1812 No additional content value encoding (i.e., BACKSLASH character 1813 encoding) is defined for this value type. 1815 Example: 1817 1234567890 1818 -1234567890 1819 +1234567890 1820 432109876 1822 4.3.9 Period of Time 1824 Value Name: PERIOD 1825 Purpose: This value type is used to identify values that contain a 1826 precise period of time. 1828 Formal Definition: The data type is defined by the following 1829 notation: 1831 period = period-explicit / period-start 1833 period-explicit = date-time "/" date-time 1834 ; [ISO 8601] complete representation basic format for a period of 1835 ; time consisting of a start and end. The start MUST be before the 1836 ; end. 1838 period-start = date-time "/" dur-value 1839 ; [ISO 8601] complete representation basic format for a period of 1840 ; time consisting of a start and positive duration of time. 1842 Description: If the property permits, multiple "period" values are 1843 specified by a COMMA character (US-ASCII decimal 44) separated list 1844 of values. There are two forms of a period of time. First, a period 1845 of time is identified by its start and its end. This format is 1846 expressed as the [ISO 8601] complete representation, basic format for 1847 "DATE-TIME" start of the period, followed by a SOLIDUS character (US- 1848 ASCII decimal 47), followed by the "DATE-TIME" of the end of the 1849 period. The start of the period MUST be before the end of the period. 1850 Second, a period of time can also be defined by a start and a 1851 positive duration of time. The format is expressed as the [ISO 8601] 1852 complete representation, basic format for the "DATE-TIME" start of 1853 the period, followed by a SOLIDUS character (US-ASCII decimal 47), 1854 followed by the [ISO 8601] basic format for "DURATION" of the period. 1856 Example: The period starting at 18:00:00 UTC, on January 1, 1997 and 1857 ending at 07:00:00 UTC on January 2, 1997 would be: 1859 19970101T180000Z/19970102T070000Z 1861 The period start at 18:00:00 on January 1, 1997 and lasting 5 hours 1862 and 30 minutes would be: 1864 19970101T180000Z/PT5H30M 1866 No additional content value encoding (i.e., BACKSLASH character 1867 encoding) is defined for this value type. 1869 4.3.10 Recurrence Rule 1871 Value Name: RECUR 1873 Purpose: This value type is used to identify properties that contain 1874 a recurrence rule specification. 1876 Formal Definition: The value type is defined by the following 1877 notation: 1879 recur = "FREQ"=freq *( 1881 ; either UNTIL or COUNT may appear in a 'recur', 1882 ; but UNTIL and COUNT MUST NOT occur in the same 'recur' 1884 ( ";" "UNTIL" "=" enddate ) / 1885 ( ";" "COUNT" "=" 1*DIGIT ) / 1887 ; the rest of these keywords are optional, 1888 ; but MUST NOT occur more than once 1890 ( ";" "INTERVAL" "=" 1*DIGIT ) / 1891 ( ";" "BYSECOND" "=" byseclist ) / 1892 ( ";" "BYMINUTE" "=" byminlist ) / 1893 ( ";" "BYHOUR" "=" byhrlist ) / 1894 ( ";" "BYDAY" "=" bywdaylist ) / 1895 ( ";" "BYMONTHDAY" "=" bymodaylist ) / 1896 ( ";" "BYYEARDAY" "=" byyrdaylist ) / 1897 ( ";" "BYWEEKNO" "=" bywknolist ) / 1898 ( ";" "BYMONTH" "=" bymolist ) / 1899 ( ";" "BYSETPOS" "=" bysplist ) / 1900 ( ";" "WKST" "=" weekday ) / 1901 ( ";" x-name "=" text ) 1902 ) 1904 freq = "SECONDLY" / "MINUTELY" / "HOURLY" / "DAILY" 1905 / "WEEKLY" / "MONTHLY" / "YEARLY" 1907 enddate = date 1908 enddate =/ date-time ;An UTC value 1910 byseclist = seconds / ( seconds *("," seconds) ) 1912 seconds = 1DIGIT / 2DIGIT ;0 to 59 1914 byminlist = minutes / ( minutes *("," minutes) ) 1916 minutes = 1DIGIT / 2DIGIT ;0 to 59 1918 byhrlist = hour / ( hour *("," hour) ) 1920 hour = 1DIGIT / 2DIGIT ;0 to 23 1922 bywdaylist = weekdaynum / ( weekdaynum *("," weekdaynum) ) 1924 weekdaynum = [([plus] ordwk / minus ordwk)] weekday 1926 plus = "+" 1928 minus = "-" 1930 ordwk = 1DIGIT / 2DIGIT ;1 to 53 1931 weekday = "SU" / "MO" / "TU" / "WE" / "TH" / "FR" / "SA" 1932 ;Corresponding to SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, 1933 ;FRIDAY, SATURDAY and SUNDAY days of the week. 1935 bymodaylist = monthdaynum / ( monthdaynum *("," monthdaynum) ) 1937 monthdaynum = ([plus] ordmoday) / (minus ordmoday) 1939 ordmoday = 1DIGIT / 2DIGIT ;1 to 31 1941 byyrdaylist = yeardaynum / ( yeardaynum *("," yeardaynum) ) 1943 yeardaynum = ([plus] ordyrday) / (minus ordyrday) 1945 ordyrday = 1DIGIT / 2DIGIT / 3DIGIT ;1 to 366 1947 bywknolist = weeknum / ( weeknum *("," weeknum) ) 1949 weeknum = ([plus] ordwk) / (minus ordwk) 1951 bymolist = monthnum / ( monthnum *("," monthnum) ) 1953 monthnum = 1DIGIT / 2DIGIT ;1 to 12 1955 bysplist = setposday / ( setposday *("," setposday) ) 1957 setposday = yeardaynum 1959 Description: If the property permits, multiple "recur" values are 1960 specified by a COMMA character (US-ASCII decimal 44) separated list 1961 of values. The value type is a structured value consisting of a list 1962 of one or more recurrence grammar parts. Each rule part is defined by 1963 a NAME=VALUE pair. The rule parts are separated from each other by 1964 the SEMICOLON character (US-ASCII decimal 59). The rule parts are not 1965 ordered in any particular sequence. Individual rule parts MUST only 1966 be specified once. 1968 The FREQ rule part identifies the type of recurrence rule. This rule 1969 part MUST be specified in the recurrence rule. Valid values include 1970 SECONDLY, to specify repeating events based on an interval of a 1971 second or more; MINUTELY, to specify repeating events based on an 1972 interval of a minute or more; HOURLY, to specify repeating events 1973 based on an interval of an hour or more; DAILY, to specify repeating 1974 events based on an interval of a day or more; WEEKLY, to specify 1975 repeating events based on an interval of a week or more; MONTHLY, to 1976 specify repeating events based on an interval of a month or more; and 1977 YEARLY, to specify repeating events based on an interval of a year or 1978 more. 1980 The INTERVAL rule part contains a positive integer representing how 1981 often the recurrence rule repeats. The default value is "1", meaning 1982 every second for a SECONDLY rule, or every minute for a MINUTELY 1983 rule, every hour for an HOURLY rule, every day for a DAILY rule, 1984 every week for a WEEKLY rule, every month for a MONTHLY rule and 1985 every year for a YEARLY rule. 1987 The UNTIL rule part defines a date-time value which bounds the 1988 recurrence rule in an inclusive manner. If the value specified by 1989 UNTIL is synchronized with the specified recurrence, this date or 1990 date-time becomes the last instance of the recurrence. If specified 1991 as a date-time value, then it MUST be specified in an UTC time 1992 format. If not present, and the COUNT rule part is also not present, 1993 the RRULE is considered to repeat forever. 1995 The COUNT rule part defines the number of occurrences at which to 1996 range-bound the recurrence. The "DTSTART" property value, if 1997 specified, counts as the first occurrence. 1999 The BYSECOND rule part specifies a COMMA character (US-ASCII decimal 2000 44) separated list of seconds within a minute. Valid values are 0 to 2001 59. The BYMINUTE rule part specifies a COMMA character (US-ASCII 2002 decimal 44) separated list of minutes within an hour. Valid values 2003 are 0 to 59. The BYHOUR rule part specifies a COMMA character (US- 2004 ASCII decimal 44) separated list of hours of the day. Valid values 2005 are 0 to 23. 2007 The BYDAY rule part specifies a COMMA character (US-ASCII decimal 44) 2008 separated list of days of the week; MO indicates Monday; TU indicates 2009 Tuesday; WE indicates Wednesday; TH indicates Thursday; FR indicates 2010 Friday; SA indicates Saturday; SU indicates Sunday. 2012 Each BYDAY value can also be preceded by a positive (+n) or negative 2013 (-n) integer. If present, this indicates the nth occurrence of the 2014 specific day within the MONTHLY or YEARLY RRULE. For example, within 2015 a MONTHLY rule, +1MO (or simply 1MO) represents the first Monday 2016 within the month, whereas -1MO represents the last Monday of the 2017 month. If an integer modifier is not present, it means all days of 2018 this type within the specified frequency. For example, within a 2019 MONTHLY rule, MO represents all Mondays within the month. 2021 The BYMONTHDAY rule part specifies a COMMA character (ASCII decimal 2022 44) separated list of days of the month. Valid values are 1 to 31 or 2023 -31 to -1. For example, -10 represents the tenth to the last day of 2024 the month. 2026 The BYYEARDAY rule part specifies a COMMA character (US-ASCII 2027 decimal 44) separated list of days of the year. Valid values are 1 to 2028 366 or -366 to -1. For example, -1 represents the last day of the 2029 year (December 31st) and -306 represents the 306th to the last day of 2030 the year (March 1st). 2032 The BYWEEKNO rule part specifies a COMMA character (US-ASCII decimal 2033 44) separated list of ordinals specifying weeks of the year. Valid 2034 values are 1 to 53 or -53 to -1. This corresponds to weeks according 2035 to week numbering as defined in [ISO 8601]. A week is defined as a 2036 seven day period, starting on the day of the week defined to be the 2037 week start (see WKST). Week number one of the calendar year is the 2038 first week which contains at least four (4) days in that calendar 2039 year. This rule part is only valid for YEARLY rules. For example, 3 2040 represents the third week of the year. 2042 Note: Assuming a Monday week start, week 53 can only occur when 2043 Thursday is January 1 or if it is a leap year and Wednesday is 2044 January 1. 2046 The BYMONTH rule part specifies a COMMA character (US-ASCII decimal 2047 44) separated list of months of the year. Valid values are 1 to 12. 2049 The WKST rule part specifies the day on which the workweek starts. 2050 Valid values are MO, TU, WE, TH, FR, SA and SU. This is significant 2051 when a WEEKLY RRULE has an interval greater than 1, and a BYDAY rule 2052 part is specified. This is also significant when in a YEARLY RRULE 2053 when a BYWEEKNO rule part is specified. The default value is MO. 2055 The BYSETPOS rule part specifies a COMMA character (US-ASCII decimal 2056 44) separated list of values which corresponds to the nth occurrence 2057 within the set of events specified by the rule. Valid values are 1 to 2058 366 or -366 to -1. It MUST only be used in conjunction with another 2059 BYxxx rule part. For example "the last work day of the month" could 2060 be represented as: 2062 RRULE:FREQ=MONTHLY;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-1 2064 Each BYSETPOS value can include a positive (+n) or negative (-n) 2065 integer. If present, this indicates the nth occurrence of the 2066 specific occurrence within the set of events specified by the rule. 2068 If BYxxx rule part values are found which are beyond the available 2069 scope (ie, BYMONTHDAY=30 in February), they are simply ignored. 2071 Information, not contained in the rule, necessary to determine the 2072 various recurrence instance start time and dates are derived from the 2073 Start Time (DTSTART) entry attribute. For example, 2074 "FREQ=YEARLY;BYMONTH=1" doesn't specify a specific day within the 2075 month or a time. This information would be the same as what is 2076 specified for DTSTART. 2078 BYxxx rule parts modify the recurrence in some manner. BYxxx rule 2079 parts for a period of time which is the same or greater than the 2080 frequency generally reduce or limit the number of occurrences of the 2081 recurrence generated. For example, "FREQ=DAILY;BYMONTH=1" reduces the 2082 number of recurrence instances from all days (if BYMONTH tag is not 2083 present) to all days in January. BYxxx rule parts for a period of 2084 time less than the frequency generally increase or expand the number 2085 of occurrences of the recurrence. For example, 2086 "FREQ=YEARLY;BYMONTH=1,2" increases the number of days within the 2087 yearly recurrence set from 1 (if BYMONTH tag is not present) to 2. 2089 If multiple BYxxx rule parts are specified, then after evaluating the 2090 specified FREQ and INTERVAL rule parts, the BYxxx rule parts are 2091 applied to the current set of evaluated occurrences in the following 2092 order: BYMONTH, BYWEEKNO, BYYEARDAY, BYMONTHDAY, BYDAY, BYHOUR, 2093 BYMINUTE, BYSECOND and BYSETPOS; then COUNT and UNTIL are evaluated. 2095 Here is an example of evaluating multiple BYxxx rule parts. 2097 DTSTART;TZID=US-Eastern:19970105T083000 2098 RRULE:FREQ=YEARLY;INTERVAL=2;BYMONTH=1;BYDAY=SU;BYHOUR=8,9; 2099 BYMINUTE=30 2101 First, the "INTERVAL=2" would be applied to "FREQ=YEARLY" to arrive 2102 at "every other year". Then, "BYMONTH=1" would be applied to arrive 2103 at "every January, every other year". Then, "BYDAY=SU" would be 2104 applied to arrive at "every Sunday in January, every other year". 2105 Then, "BYHOUR=8,9" would be applied to arrive at "every Sunday in 2106 January at 8 AM and 9 AM, every other year". Then, "BYMINUTE=30" 2107 would be applied to arrive at "every Sunday in January at 8:30 AM and 2108 9:30 AM, every other year". Then, lacking information from RRULE, the 2109 second is derived from DTSTART, to end up in "every Sunday in January 2110 at 8:30:00 AM and 9:30:00 AM, every other year". Similarly, if the 2111 BYMINUTE, BYHOUR, BYDAY, BYMONTHDAY or BYMONTH rule part were 2112 missing, the appropriate minute, hour, day or month would have been 2113 retrieved from the "DTSTART" property. 2115 No additional content value encoding (i.e., BACKSLASH character 2116 encoding) is defined for this value type. 2118 Example: The following is a rule which specifies 10 meetings which 2119 occur every other day: 2121 FREQ=DAILY;COUNT=10;INTERVAL=2 2123 There are other examples specified in the "RRULE" specification. 2125 4.3.11 Text 2127 Value Name: TEXT 2129 Purpose This value type is used to identify values that contain human 2130 readable text. 2132 Formal Definition: The character sets supported by this revision of 2133 iCalendar are UTF-8 and US ASCII thereof. The applicability to other 2134 character sets is for future work. The value type is defined by the 2135 following notation. 2137 text = *(TSAFE-CHAR / ":" / DQUOTE / ESCAPED-CHAR) 2138 ; Folded according to description above 2140 ESCAPED-CHAR = "\\" / "\;" / "\," / "\N" / "\n") 2141 ; \\ encodes \, \N or \n encodes newline 2142 ; \; encodes ;, \, encodes , 2144 TSAFE-CHAR = %x20-21 / %x23-2B / %x2D-39 / %x3C-5B 2145 %x5D-7E / NON-US-ASCII 2146 ; Any character except CTLs not needed by the current 2147 ; character set, DQUOTE, ";", ":", "\", "," 2149 Note: Certain other character sets may require modification of the 2150 above definitions, but this is beyond the scope of this document. 2152 Description: If the property permits, multiple "text" values are 2153 specified by a COMMA character (US-ASCII decimal 44) separated list 2154 of values. 2156 The language in which the text is represented can be controlled by 2157 the "LANGUAGE" property parameter. 2159 An intentional formatted text line break MUST only be included in a 2160 "TEXT" property value by representing the line break with the 2161 character sequence of BACKSLASH (US-ASCII decimal 92), followed by a 2162 LATIN SMALL LETTER N (US-ASCII decimal 110) or a LATIN CAPITAL LETTER 2163 N (US-ASCII decimal 78), that is "\n" or "\N". 2165 The "TEXT" property values may also contain special characters that 2166 are used to signify delimiters, such as a COMMA character for lists 2167 of values or a SEMICOLON character for structured values. In order to 2168 support the inclusion of these special characters in "TEXT" property 2169 values, they MUST be escaped with a BACKSLASH character. A BACKSLASH 2170 character (US-ASCII decimal 92) in a "TEXT" property value MUST be 2171 escaped with another BACKSLASH character. A COMMA character in a 2172 "TEXT" property value MUST be escaped with a BACKSLASH character (US- 2173 ASCII decimal 92). A SEMICOLON character in a "TEXT" property value 2174 MUST be escaped with a BACKSLASH character (US-ASCII decimal 92). 2175 However, a COLON character in a "TEXT" property value SHALL NOT be 2176 escaped with a BACKSLASH character.Example: A multiple line value of: 2178 Project XYZ Final Review 2179 Conference Room - 3B 2180 Come Prepared. 2182 would be represented as: 2184 Project XYZ Final Review\nConference Room - 3B\nCome Prepared. 2186 4.3.12 Time 2188 Value Name: TIME 2190 Purpose: This value type is used to identify values that contain a 2191 time of day. 2193 Formal Definition: The data type is defined by the following 2194 notation: 2196 time = time-hour time-minute time-second [time-utc] 2198 time-hour = 2DIGIT ;00-23 2199 time-minute = 2DIGIT ;00-59 2200 time-second = 2DIGIT ;00-60 2201 ;The "60" value is used to account for "leap" seconds. 2203 time-utc = "Z" 2205 Description: If the property permits, multiple "time" values are 2206 specified by a COMMA character (US-ASCII decimal 44) separated list 2207 of values. No additional content value encoding (i.e., BACKSLASH 2208 character encoding) is defined for this value type. 2210 The "TIME" data type is used to identify values that contain a time 2211 of day. The format is based on the [ISO 8601] complete 2212 representation, basic format for a time of day. The text format 2213 consists of a two-digit 24-hour of the day (i.e., values 0-23), two- 2214 digit minute in the hour (i.e., values 0-59), and two-digit seconds 2215 in the minute (i.e., values 0-60). The seconds value of 60 MUST only 2216 to be used to account for "leap" seconds. Fractions of a second are 2217 not supported by this format. 2219 In parallel to the "DATE-TIME" definition above, the "TIME" data type 2220 expresses time values in three forms: 2222 The form of time with UTC offset MUST NOT be used. For example, the 2223 following is NOT VALID for a time value: 2225 230000-0800 ;Invalid time format 2227 FORM #1 LOCAL TIME 2229 The local time form is simply a time value that does not contain the 2230 UTC designator nor does it reference a time zone. For example, 11:00 2231 PM: 2233 230000 2235 Time values of this type are said to be "floating" and are not bound 2236 to any time zone in particular. They are used to represent the same 2237 hour, minute, and second value regardless of which time zone is 2238 currently being observed. For example, an event can be defined that 2239 indicates that an individual will be busy from 11:00 AM to 1:00 PM 2240 every day, no matter which time zone the person is in. In these 2241 cases, a local time can be specified. The recipient of an iCalendar 2242 object with a property value consisting of a local time, without any 2243 relative time zone information, SHOULD interpret the value as being 2244 fixed to whatever time zone the ATTENDEE is in at any given moment. 2245 This means that two ATTENDEEs may participate in the same event at 2246 different UTC times; floating time SHOULD only be used where that is 2247 reasonable behavior. 2249 In most cases, a fixed time is desired. To properly communicate a 2250 fixed time in a property value, either UTC time or local time with 2251 time zone reference MUST be specified. 2253 The use of local time in a TIME value without the TZID property 2254 parameter is to be interpreted as a local time value, regardless of 2255 the existence of "VTIMEZONE" calendar components in the iCalendar 2256 object. 2258 FORM #2: UTC TIME 2260 UTC time, or absolute time, is identified by a LATIN CAPITAL LETTER Z 2261 suffix character (US-ASCII decimal 90), the UTC designator, appended 2262 to the time value. For example, the following represents 07:00 AM 2263 UTC: 2265 070000Z 2267 The TZID property parameter MUST NOT be applied to TIME properties 2268 whose time values are specified in UTC. 2270 FORM #3: LOCAL TIME AND TIME ZONE REFERENCE 2272 The local time with reference to time zone information form is 2273 identified by the use the TZID property parameter to reference the 2274 appropriate time zone definition. TZID is discussed in detail in the 2275 section on Time Zone. 2277 Example: The following represents 8:30 AM in New York in Winter, five 2278 hours behind UTC, in each of the three formats using the "X- 2279 TIMEOFDAY" non-standard property: 2281 X-TIMEOFDAY:083000 2283 X-TIMEOFDAY:133000Z 2285 X-TIMEOFDAY;TZID=US-Eastern:083000 2287 4.3.13 URI 2289 Value Name: URI 2291 Purpose: This value type is used to identify values that contain a 2292 uniform resource identifier (URI) type of reference to the property 2293 value. 2295 Formal Definition: The data type is defined by the following 2296 notation: 2298 uri = 2300 Description: This data type might be used to reference binary 2301 information, for values that are large, or otherwise undesirable to 2302 include directly in the iCalendar object. 2304 The URI value formats in RFC 1738, RFC 2111 and any other IETF 2305 registered value format can be specified. 2307 Any IANA registered URI format can be used. These include, but are 2308 not limited to, those defined in RFC 1738 and RFC 2111. 2310 When a property parameter value is a URI value type, the URI MUST be 2311 specified as a quoted-string value. 2313 No additional content value encoding (i.e., BACKSLASH character 2314 encoding) is defined for this value type. 2316 Example: The following is a URI for a network file: 2318 http://host1.com/my-report.txt 2320 4.3.14 UTC Offset 2322 Value Name: UTC-OFFSET 2324 Purpose: This value type is used to identify properties that contain 2325 an offset from UTC to local time. 2327 Formal Definition: The data type is defined by the following 2328 notation: 2330 utc-offset = time-numzone ;As defined above in time data type 2332 time-numzone = ("+" / "-") time-hour time-minute [time- 2333 second] 2335 Description: The PLUS SIGN character MUST be specified for positive 2336 UTC offsets (i.e., ahead of UTC). The value of "-0000" and "-000000" 2337 are not allowed. The time-second, if present, may not be 60; if 2338 absent, it defaults to zero. 2340 No additional content value encoding (i.e., BACKSLASH character 2341 encoding) is defined for this value type. 2343 Example: The following UTC offsets are given for standard time for 2344 New York (five hours behind UTC) and Geneva (one hour ahead of UTC): 2346 -0500 2348 +0100 2350 4.4 iCalendar Object 2352 The Calendaring and Scheduling Core Object is a collection of 2353 calendaring and scheduling information. Typically, this information 2354 will consist of a single iCalendar object. However, multiple 2355 iCalendar objects can be sequentially grouped together. The first 2356 line and last line of the iCalendar object MUST contain a pair of 2357 iCalendar object delimiter strings. The syntax for an iCalendar 2358 object is as follows: 2360 icalobject = 1*("BEGIN" ":" "VCALENDAR" CRLF 2361 icalbody 2362 "END" ":" "VCALENDAR" CRLF) 2364 The following is a simple example of an iCalendar object: 2366 BEGIN:VCALENDAR 2367 VERSION:2.0 2368 PRODID:-//hacksw/handcal//NONSGML v1.0//EN 2369 BEGIN:VEVENT 2370 DTSTART:19970714T170000Z 2371 DTEND:19970715T035959Z 2372 SUMMARY:Bastille Day Party 2373 END:VEVENT 2374 END:VCALENDAR 2376 4.5 Property 2378 A property is the definition of an individual attribute describing a 2379 calendar or a calendar component. A property takes the form defined 2380 by the "contentline" notation defined in section 4.1.1. 2382 The following is an example of a property: 2384 DTSTART:19960415T133000Z 2386 This memo imposes no ordering of properties within an iCalendar 2387 object. 2389 Property names, parameter names and enumerated parameter values are 2390 case insensitive. For example, the property name "DUE" is the same as 2391 "due" and "Due", DTSTART;TZID=US-Eastern:19980714T120000 is the same 2392 as DtStart;TzID=US-Eastern:19980714T120000. 2394 4.6 Calendar Components 2396 The body of the iCalendar object consists of a sequence of calendar 2397 properties and one or more calendar components. The calendar 2398 properties are attributes that apply to the calendar as a whole. The 2399 calendar components are collections of properties that express a 2400 particular calendar semantic. For example, the calendar component can 2401 specify an event, a to-do, a journal entry, time zone information, or 2402 free/busy time information, or an alarm. 2404 The body of the iCalendar object is defined by the following 2405 notation: 2407 icalbody = calprops component 2409 calprops = 2*( 2411 ; 'prodid' and 'version' are both REQUIRED, 2412 ; but MUST NOT occur more than once 2413 prodid /version / 2415 ; 'calscale' and 'method' are optional, 2416 ; but MUST NOT occur more than once 2418 calscale / 2419 method / 2421 x-prop 2423 ) 2425 component = 1*(eventc / todoc / journalc / freebusyc / 2426 / timezonec / iana-comp / x-comp) 2428 iana-comp = "BEGIN" ":" iana-token CRLF 2430 1*contentline 2432 "END" ":" iana-token CRLF 2434 x-comp = "BEGIN" ":" x-name CRLF 2436 1*contentline 2438 "END" ":" x-name CRLF 2440 An iCalendar object MUST include the "PRODID" and "VERSION" calendar 2441 properties. In addition, it MUST include at least one calendar 2442 component. Special forms of iCalendar objects are possible to publish 2443 just busy time (i.e., only a "VFREEBUSY" calendar component) or time 2444 zone (i.e., only a "VTIMEZONE" calendar component) information. In 2445 addition, a complex iCalendar object is possible that is used to 2446 capture a complete snapshot of the contents of a calendar (e.g., 2447 composite of many different calendar components). More commonly, an 2448 iCalendar object will consist of just a single "VEVENT", "VTODO" or 2449 "VJOURNAL" calendar component. 2451 4.6.1 Event Component 2453 Component Name: "VEVENT" 2455 Purpose: Provide a grouping of component properties that describe an 2456 event. 2458 Format Definition: A "VEVENT" calendar component is defined by the 2459 following notation: 2461 eventc = "BEGIN" ":" "VEVENT" CRLF 2462 eventprop *alarmc 2463 "END" ":" "VEVENT" CRLF 2465 eventprop = *( 2466 ; the following are optional, 2467 ; but MUST NOT occur more than once 2469 class / created / description / dtstart / geo / 2470 last-mod / location / organizer / priority / 2471 dtstamp / seq / status / summary / transp / 2472 uid / url / recurid / 2474 ; either 'dtend' or 'duration' may appear in 2475 ; a 'eventprop', but 'dtend' and 'duration' 2476 ; MUST NOT occur in the same 'eventprop' 2478 dtend / duration / 2480 ; the following are optional, 2481 ; and MAY occur more than once 2483 attach / attendee / categories / comment / 2484 contact / exdate / exrule / rstatus / related / 2485 resources / rdate / rrule / x-prop 2487 ) 2489 Description: A "VEVENT" calendar component is a grouping of component 2490 properties, and possibly including "VALARM" calendar components, that 2491 represents a scheduled amount of time on a calendar. For example, it 2492 can be an activity; such as a one-hour long, department meeting from 2493 8:00 AM to 9:00 AM, tomorrow. Generally, an event will take up time 2494 on an individual calendar. Hence, the event will appear as an opaque 2495 interval in a search for busy time. Alternately, the event can have 2496 its Time Transparency set to "TRANSPARENT" in order to prevent 2497 blocking of the event in searches for busy time. 2499 The "VEVENT" is also the calendar component used to specify an 2500 anniversary or daily reminder within a calendar. These events have a 2501 DATE value type for the "DTSTART" property instead of the default 2502 data type of DATE-TIME. If such a "VEVENT" has a "DTEND" property, it 2503 MUST be specified as a DATE value also. The anniversary type of 2504 "VEVENT" can span more than one date (i.e, "DTEND" property value is 2505 set to a calendar date after the "DTSTART" property value). 2507 The "DTSTART" property for a "VEVENT" specifies the inclusive start 2508 of the event. For recurring events, it also specifies the very first 2509 instance in the recurrence set. The "DTEND" property for a "VEVENT" 2510 calendar component specifies the non-inclusive end of the event. For 2511 cases where a "VEVENT" calendar component specifies a "DTSTART" 2512 property with a DATE data type but no "DTEND" property, the events 2513 non-inclusive end is the end of the calendar date specified by the 2514 "DTSTART" property. For cases where a "VEVENT" calendar component 2515 specifies a "DTSTART" property with a DATE-TIME data type but no 2516 "DTEND" property, the event ends on the same calendar date and time 2517 of day specified by the "DTSTART" property. 2519 The "VEVENT" calendar component cannot be nested within another 2520 calendar component. However, "VEVENT" calendar components can be 2521 related to each other or to a "VTODO" or to a "VJOURNAL" calendar 2522 component with the "RELATED-TO" property. 2524 Example: The following is an example of the "VEVENT" calendar 2525 component used to represent a meeting that will also be opaque to 2526 searches for busy time: 2528 BEGIN:VEVENT 2529 UID:19970901T130000Z-123401@host.com 2530 DTSTAMP:19970901T1300Z 2531 DTSTART:19970903T163000Z 2532 DTEND:19970903T190000Z 2533 SUMMARY:Annual Employee Review 2534 CLASS:PRIVATE 2535 CATEGORIES:BUSINESS,HUMAN RESOURCES 2536 END:VEVENT 2538 The following is an example of the "VEVENT" calendar component used 2539 to represent a reminder that will not be opaque, but rather 2540 transparent, to searches for busy time: 2542 BEGIN:VEVENT 2543 UID:19970901T130000Z-123402@host.com 2544 DTSTAMP:19970901T1300Z 2545 DTSTART:19970401T163000Z 2546 DTEND:19970402T010000Z 2547 SUMMARY:Laurel is in sensitivity awareness class. 2548 CLASS:PUBLIC 2549 CATEGORIES:BUSINESS,HUMAN RESOURCES 2550 TRANSP:TRANSPARENT 2551 END:VEVENT 2553 The following is an example of the "VEVENT" calendar component used 2554 to represent an anniversary that will occur annually. Since it takes 2555 up no time, it will not appear as opaque in a search for busy time; 2556 no matter what the value of the "TRANSP" property indicates: 2558 BEGIN:VEVENT 2559 UID:19970901T130000Z-123403@host.com 2560 DTSTAMP:19970901T1300Z 2561 DTSTART:19971102 2562 SUMMARY:Our Blissful Anniversary 2563 CLASS:CONFIDENTIAL 2564 CATEGORIES:ANNIVERSARY,PERSONAL,SPECIAL OCCASION 2565 RRULE:FREQ=YEARLY 2566 END:VEVENT 2568 4.6.2 To-do Component 2570 Component Name: VTODO 2571 Purpose: Provide a grouping of calendar properties that describe a 2572 to-do. 2574 Formal Definition: A "VTODO" calendar component is defined by the 2575 following notation: 2577 todoc = "BEGIN" ":" "VTODO" CRLF 2578 todoprop *alarmc 2579 "END" ":" "VTODO" CRLF 2581 todoprop = *( 2583 ; the following are optional, 2584 ; but MUST NOT occur more than once 2586 class / completed / created / description / dtstamp / 2587 dtstart / geo / last-mod / location / organizer / 2588 percent / priority / recurid / seq / status / 2589 summary / uid / url / 2591 ; either 'due' or 'duration' may appear in 2592 ; a 'todoprop', but 'due' and 'duration' 2593 ; MUST NOT occur in the same 'todoprop' 2595 due / duration / 2597 ; the following are optional, 2598 ; and MAY occur more than once 2600 attach / attendee / categories / comment / contact / 2601 exdate / exrule / rstatus / related / resources / 2602 rdate / rrule / x-prop 2604 ) 2606 Description: A "VTODO" calendar component is a grouping of component 2607 properties and possibly "VALARM" calendar components that represent 2608 an action-item or assignment. For example, it can be used to 2609 represent an item of work assigned to an individual; such as "turn in 2610 travel expense today". 2612 The "VTODO" calendar component cannot be nested within another 2613 calendar component. However, "VTODO" calendar components can be 2614 related to each other or to a "VTODO" or to a "VJOURNAL" calendar 2615 component with the "RELATED-TO" property. 2617 A "VTODO" calendar component without the "DTSTART" and "DUE" (or 2618 "DURATION") properties specifies a to-do that will be associated with 2619 each successive calendar date, until it is completed. 2621 Example: The following is an example of a "VTODO" calendar component: 2623 BEGIN:VTODO 2624 UID:19970901T130000Z-123404@host.com 2625 DTSTAMP:19970901T1300Z 2626 DTSTART:19970415T133000Z 2627 DUE:19970416T045959Z 2628 SUMMARY:1996 Income Tax Preparation 2629 CLASS:CONFIDENTIAL 2630 CATEGORIES:FAMILY,FINANCE 2631 PRIORITY:1 2632 STATUS:NEEDS-ACTION 2633 END:VTODO 2635 4.6.3 Journal Component 2637 Component Name: VJOURNAL 2639 Purpose: Provide a grouping of component properties that describe a 2640 journal entry. 2642 Formal Definition: A "VJOURNAL" calendar component is defined by the 2643 following notation: 2645 journalc = "BEGIN" ":" "VJOURNAL" CRLF 2646 jourprop 2647 "END" ":" "VJOURNAL" CRLF 2649 jourprop = *( 2651 ; the following are optional, 2652 ; but MUST NOT occur more than once 2654 class / created / description / dtstart / dtstamp / 2655 last-mod / organizer / recurid / seq / status / 2656 summary / uid / url / 2658 ; the following are optional, 2659 ; and MAY occur more than once 2661 attach / attendee / categories / comment / 2662 contact / exdate / exrule / related / rdate / 2663 rrule / rstatus / x-prop 2665 ) 2667 Description: A "VJOURNAL" calendar component is a grouping of 2668 component properties that represent one or more descriptive text 2669 notes associated with a particular calendar date. The "DTSTART" 2670 property is used to specify the calendar date that the journal entry 2671 is associated with. Generally, it will have a DATE value data type, 2672 but it can also be used to specify a DATE-TIME value data type. 2673 Examples of a journal entry include a daily record of a legislative 2674 body or a journal entry of individual telephone contacts for the day 2675 or an ordered list of accomplishments for the day. The "VJOURNAL" 2676 calendar component can also be used to associate a document with a 2677 calendar date. 2679 The "VJOURNAL" calendar component does not take up time on a 2680 calendar. Hence, it does not play a role in free or busy time 2681 searches - - it is as though it has a time transparency value of 2682 TRANSPARENT. It is transparent to any such searches. 2684 The "VJOURNAL" calendar component cannot be nested within another 2685 calendar component. However, "VJOURNAL" calendar components can be 2686 related to each other or to a "VEVENT" or to a "VTODO" calendar 2687 component, with the "RELATED-TO" property. 2689 Example: The following is an example of the "VJOURNAL" calendar 2690 component: 2692 BEGIN:VJOURNAL 2693 UID:19970901T130000Z-123405@host.com 2694 DTSTAMP:19970901T1300Z 2695 DTSTART;VALUE=DATE:19970317 2696 SUMMARY:Staff meeting minutes 2697 DESCRIPTION:1. Staff meeting: Participants include Joe\, Lisa 2698 and Bob. Aurora project plans were reviewed. There is currently 2699 no budget reserves for this project. Lisa will escalate to 2700 management. Next meeting on Tuesday.\n 2701 2. Telephone Conference: ABC Corp. sales representative called 2702 to discuss new printer. Promised to get us a demo by Friday.\n 2703 3. Henry Miller (Handsoff Insurance): Car was totaled by tree. 2704 Is looking into a loaner car. 654-2323 (tel). 2705 END:VJOURNAL 2707 4.6.4 Free/Busy Component 2709 Component Name: VFREEBUSY 2711 Purpose: Provide a grouping of component properties that describe 2712 either a request for free/busy time, describe a response to a request 2713 for free/busy time or describe a published set of busy time. 2715 Formal Definition: A "VFREEBUSY" calendar component is defined by the 2716 following notation: 2718 freebusyc = "BEGIN" ":" "VFREEBUSY" CRLF 2719 fbprop 2720 "END" ":" "VFREEBUSY" CRLF 2722 fbprop = *( 2724 ; the following are optional, 2725 ; but MUST NOT occur more than once 2727 contact / dtstart / dtend / duration / dtstamp / 2728 organizer / uid / url / 2730 ; the following are optional, 2731 ; and MAY occur more than once 2732 attendee / comment / freebusy / rstatus / x-prop 2734 ) 2736 Description: A "VFREEBUSY" calendar component is a grouping of 2737 component properties that represents either a request for, a reply to 2738 a request for free or busy time information or a published set of 2739 busy time information. 2741 When used to request free/busy time information, the "ATTENDEE" 2742 property specifies the calendar users whose free/busy time is being 2743 requested; the "ORGANIZER" property specifies the calendar user who 2744 is requesting the free/busy time; the "DTSTART" and "DTEND" 2745 properties specify the window of time for which the free/busy time is 2746 being requested; the "UID" and "DTSTAMP" properties are specified to 2747 assist in proper sequencing of multiple free/busy time requests. 2749 When used to reply to a request for free/busy time, the "ATTENDEE" 2750 property specifies the calendar user responding to the free/busy time 2751 request; the "ORGANIZER" property specifies the calendar user that 2752 originally requested the free/busy time; the "FREEBUSY" property 2753 specifies the free/busy time information (if it exists); and the 2754 "UID" and "DTSTAMP" properties are specified to assist in proper 2755 sequencing of multiple free/busy time replies. 2757 When used to publish busy time, the "ORGANIZER" property specifies 2758 the calendar user associated with the published busy time; the 2759 "DTSTART" and "DTEND" properties specify an inclusive time window 2760 that surrounds the busy time information; the "FREEBUSY" property 2761 specifies the published busy time information; and the "DTSTAMP" 2762 property specifies the date/time that iCalendar object was created. 2764 The "VFREEBUSY" calendar component cannot be nested within another 2765 calendar component. Multiple "VFREEBUSY" calendar components can be 2766 specified within an iCalendar object. This permits the grouping of 2767 Free/Busy information into logical collections, such as monthly 2768 groups of busy time information. 2770 The "VFREEBUSY" calendar component is intended for use in iCalendar 2771 object methods involving requests for free time, requests for busy 2772 time, requests for both free and busy, and the associated replies. 2774 Free/Busy information is represented with the "FREEBUSY" property. 2775 This property provides a terse representation of time periods. One or 2776 more "FREEBUSY" properties can be specified in the "VFREEBUSY" 2777 calendar component. 2779 When present in a "VFREEBUSY" calendar component, the "DTSTART" and 2780 "DTEND" properties SHOULD be specified prior to any "FREEBUSY" 2781 properties. In a free time request, these properties can be used in 2782 combination with the "DURATION" property to represent a request for a 2783 duration of free time within a specified window of time. 2785 The recurrence properties ("RRULE", "EXRULE", "RDATE", "EXDATE") are 2786 not permitted within a "VFREEBUSY" calendar component. Any recurring 2787 events are resolved into their individual busy time periods using the 2788 "FREEBUSY" property. 2790 Example: The following is an example of a "VFREEBUSY" calendar 2791 component used to request free or busy time information: 2793 BEGIN:VFREEBUSY 2794 ORGANIZER:MAILTO:jane_doe@host1.com 2795 ATTENDEE:MAILTO:john_public@host2.com 2796 DTSTART:19971015T050000Z 2797 DTEND:19971016T050000Z 2798 DTSTAMP:19970901T083000Z 2799 END:VFREEBUSY 2801 The following is an example of a "VFREEBUSY" calendar component used 2802 to reply to the request with busy time information: 2804 BEGIN:VFREEBUSY 2805 ORGANIZER:MAILTO:jane_doe@host1.com 2806 ATTENDEE:MAILTO:john_public@host2.com 2807 DTSTAMP:19970901T100000Z 2808 FREEBUSY;VALUE=PERIOD:19971015T050000Z/PT8H30M, 2809 19971015T160000Z/PT5H30M,19971015T223000Z/PT6H30M 2810 URL:http://host2.com/pub/busy/jpublic-01.ifb 2811 COMMENT:This iCalendar file contains busy time information for 2812 the next three months. 2813 END:VFREEBUSY 2815 The following is an example of a "VFREEBUSY" calendar component used 2816 to publish busy time information. 2818 BEGIN:VFREEBUSY 2819 ORGANIZER:jsmith@host.com 2820 DTSTART:19980313T141711Z 2821 DTEND:19980410T141711Z 2822 FREEBUSY:19980314T233000Z/19980315T003000Z 2823 FREEBUSY:19980316T153000Z/19980316T163000Z 2824 FREEBUSY:19980318T030000Z/19980318T040000Z 2825 URL:http://www.host.com/calendar/busytime/jsmith.ifb 2826 END:VFREEBUSY 2828 4.6.5 Time Zone Component 2830 Component Name: VTIMEZONE 2832 Purpose: Provide a grouping of component properties that defines a 2833 time zone. 2835 Formal Definition: A "VTIMEZONE" calendar component is defined by the 2836 following notation: 2838 timezonec = "BEGIN" ":" "VTIMEZONE" CRLF 2839 2*( 2841 ; 'tzid' is required, but MUST NOT occur more 2842 ; than once 2844 tzid / 2846 ; 'last-mod' and 'tzurl' are optional, 2847 but MUST NOT occur more than once 2849 last-mod / tzurl / 2851 ; one of 'standardc' or 'daylightc' MUST occur 2852 ..; and each MAY occur more than once. 2854 standardc / daylightc / 2856 ; the following is optional, 2857 ; and MAY occur more than once 2859 x-prop 2861 ) 2863 "END" ":" "VTIMEZONE" CRLF 2865 standardc = "BEGIN" ":" "STANDARD" CRLF 2867 tzprop 2869 "END" ":" "STANDARD" CRLF 2871 daylightc = "BEGIN" ":" "DAYLIGHT" CRLF 2873 tzprop 2875 "END" ":" "DAYLIGHT" CRLF 2877 tzprop = 3*( 2879 ; the following are each REQUIRED, 2880 ; but MUST NOT occur more than once 2882 dtstart / tzoffsetto / tzoffsetfrom / 2884 ; the following are optional, 2885 ; and MAY occur more than once 2887 comment / rdate / rrule / tzname / x-prop 2889 ) 2891 Description: A time zone is unambiguously defined by the set of time 2892 measurement rules determined by the governing body for a given 2893 geographic area. These rules describe at a minimum the base offset 2894 from UTC for the time zone, often referred to as the Standard Time 2895 offset. Many locations adjust their Standard Time forward or backward 2896 by one hour, in order to accommodate seasonal changes in number of 2897 daylight hours, often referred to as Daylight Saving Time. Some 2898 locations adjust their time by a fraction of an hour. Standard Time 2899 is also known as Winter Time. Daylight Saving Time is also known as 2900 Advanced Time, Summer Time, or Legal Time in certain countries. The 2901 following table shows the changes in time zone rules in effect for 2902 New York City starting from 1967. Each line represents a description 2903 or rule for a particular observance. 2905 Effective Observance Rule 2907 Date (Date/Time) Offset Abbreviation 2909 1967-* last Sun in Oct, 02:00 -0500 EST 2911 1967-1973 last Sun in Apr, 02:00 -0400 EDT 2913 1974-1974 Jan 6, 02:00 -0400 EDT 2915 1975-1975 Feb 23, 02:00 -0400 EDT 2917 1976-1986 last Sun in Apr, 02:00 -0400 EDT 2919 1987-* first Sun in Apr, 02:00 -0400 EDT 2921 Note: The specification of a global time zone registry is not 2922 addressed by this document and is left for future study. 2923 However, implementers may find the Olson time zone database [TZ] 2924 a useful reference. It is an informal, public-domain collection 2925 of time zone information, which is currently being maintained by 2926 volunteer Internet participants, and is used in several 2927 operating systems. This database contains current and historical 2928 time zone information for a wide variety of locations around the 2929 globe; it provides a time zone identifier for every unique time 2930 zone rule set in actual use since 1970, with historical data 2931 going back to the introduction of standard time. 2933 Interoperability between two calendaring and scheduling applications, 2934 especially for recurring events, to-dos or journal entries, is 2935 dependent on the ability to capture and convey date and time 2936 information in an unambiguous format. The specification of current 2937 time zone information is integral to this behavior. 2939 If present, the "VTIMEZONE" calendar component defines the set of 2940 Standard Time and Daylight Saving Time observances (or rules) for a 2941 particular time zone for a given interval of time. The "VTIMEZONE" 2942 calendar component cannot be nested within other calendar components. 2943 Multiple "VTIMEZONE" calendar components can exist in an iCalendar 2944 object. In this situation, each "VTIMEZONE" MUST represent a unique 2945 time zone definition. This is necessary for some classes of events, 2946 such as airline flights, that start in one time zone and end in 2947 another. 2949 The "VTIMEZONE" calendar component MUST be present if the iCalendar 2950 object contains an RRULE that generates dates on both sides of a time 2951 zone shift (e.g. both in Standard Time and Daylight Saving Time) 2952 unless the iCalendar object intends to convey a floating time (See 2953 the section "4.1.10.11 Time" for proper interpretation of floating 2954 time). It can be present if the iCalendar object does not contain 2955 such a RRULE. In addition, if a RRULE is present, there MUST be valid 2956 time zone information for all recurrence instances. 2958 The "VTIMEZONE" calendar component MUST include the "TZID" property 2959 and at least one definition of a standard or daylight component. The 2960 standard or daylight component MUST include the "DTSTART", 2961 "TZOFFSETFROM" and "TZOFFSETTO" properties. 2963 An individual "VTIMEZONE" calendar component MUST be specified for 2964 each unique "TZID" parameter value specified in the iCalendar object. 2966 Each "VTIMEZONE" calendar component consists of a collection of one 2967 or more sub-components that describe the rule for a particular 2968 observance (either a Standard Time or a Daylight Saving Time 2969 observance). The "STANDARD" sub-component consists of a collection of 2970 properties that describe Standard Time. The "DAYLIGHT" sub-component 2971 consists of a collection of properties that describe Daylight Saving 2972 Time. In general this collection of properties consists of: 2974 - the first onset date-time for the observance 2976 - the last onset date-time for the observance, if a last onset 2977 is known. 2979 - the offset to be applied for the observance 2981 - a rule that describes the day and time when the observance 2982 takes effect 2984 - an optional name for the observance 2986 For a given time zone, there may be multiple unique definitions of 2987 the observances over a period of time. Each observance is described 2988 using either a "STANDARD" or "DAYLIGHT" sub-component. The collection 2989 of these sub-components is used to describe the time zone for a given 2990 period of time. The offset to apply at any given time is found by 2991 locating the observance that has the last onset date and time before 2992 the time in question, and using the offset value from that 2993 observance. 2995 The top-level properties in a "VTIMEZONE" calendar component are: 2997 The mandatory "TZID" property is a text value that uniquely 2998 identifies the VTIMZONE calendar component within the scope of an 2999 iCalendar object. 3001 The optional "LAST-MODIFIED" property is a UTC value that specifies 3002 the date and time that this time zone definition was last updated. 3004 The optional "TZURL" property is url value that points to a published 3005 VTIMEZONE definition. TZURL SHOULD refer to a resource that is 3006 accessible by anyone who might need to interpret the object. This 3007 SHOULD NOT normally be a file: URL or other URL that is not widely- 3008 accessible. 3010 The collection of properties that are used to define the STANDARD and 3011 DAYLIGHT sub-components include: 3013 The mandatory "DTSTART" property gives the effective onset date and 3014 local time for the time zone sub-component definition. "DTSTART" in 3015 this usage MUST be specified as a local DATE-TIME value. 3017 The mandatory "TZOFFSETFROM" property gives the UTC offset which is 3018 in use when the onset of this time zone observance begins. 3019 "TZOFFSETFROM" is combined with "DTSTART" to define the effective 3020 onset for the time zone sub-component definition. For example, the 3021 following represents the time at which the observance of Standard 3022 Time took effect in Fall 1967 for New York City: 3024 DTSTART:19671029T020000 3026 TZOFFSETFROM:-0400 3028 The mandatory "TZOFFSETTO " property gives the UTC offset for the 3029 time zone sub-component (Standard Time or Daylight Saving Time) when 3030 this observance is in use. 3032 The optional "TZNAME" property is the customary name for the time 3033 zone. It may be specified multiple times, to allow for specifying 3034 multiple language variants of the time zone names. This could be used 3035 for displaying dates. 3037 If specified, the onset for the observance defined by the time zone 3038 sub-component is defined by either the "RRULE" or "RDATE" property. 3039 If neither is specified, only one sub-component can be specified in 3040 the "VTIMEZONE" calendar component and it is assumed that the single 3041 observance specified is always in effect. 3043 The "RRULE" property defines the recurrence rule for the onset of the 3044 observance defined by this time zone sub-component. Some specific 3045 requirements for the usage of RRULE for this purpose include: 3047 - If observance is known to have an effective end date, the 3048 "UNTIL" recurrence rule parameter MUST be used to specify the 3049 last valid onset of this observance (i.e., the UNTIL date-time 3050 will be equal to the last instance generated by the recurrence 3051 pattern). It MUST be specified in UTC time. 3053 - The "DTSTART" and the "TZOFFSETTO" properties MUST be used 3054 when generating the onset date-time values (instances) from the 3055 RRULE. 3057 Alternatively, the "RDATE" property can be used to define the onset 3058 of the observance by giving the individual onset date and times. 3059 "RDATE" in this usage MUST be specified as a local DATE-TIME value in 3060 UTC time. 3062 The optional "COMMENT" property is also allowed for descriptive 3063 explanatory text. 3065 Example: The following are examples of the "VTIMEZONE" calendar 3066 component: 3068 This is an example showing time zone information for the Eastern 3069 United States using "RDATE" property. Note that this is only suitable 3070 for a recurring event that starts on or later than April 6, 1997 at 3071 03:00:00 EDT (i.e., the earliest effective transition date and time) 3072 and ends no later than April 7, 1998 02:00:00 EST (i.e., latest valid 3073 date and time for EST in this scenario). For example, this can be 3074 used for a recurring event that occurs every Friday, 8am-9:00 AM, 3075 starting June 1, 1997, ending December 31, 1997. 3077 BEGIN:VTIMEZONE 3078 TZID:US-Eastern 3079 LAST-MODIFIED:19870101T000000Z 3080 BEGIN:STANDARD 3081 DTSTART:19971026T020000 3082 RDATE:19971026T020000 3083 TZOFFSETFROM:-0400 3084 TZOFFSETTO:-0500 3085 TZNAME:EST 3086 END:STANDARD 3087 BEGIN:DAYLIGHT 3088 DTSTART:19971026T020000 3089 RDATE:19970406T020000 3090 TZOFFSETFROM:-0500 3091 TZOFFSETTO:-0400 3092 TZNAME:EDT 3093 END:DAYLIGHT 3094 END:VTIMEZONE 3096 This is a simple example showing the current time zone rules for the 3097 Eastern United States using a RRULE recurrence pattern. Note that 3098 there is no effective end date to either of the Standard Time or 3099 Daylight Time rules. This information would be valid for a recurring 3100 event starting today and continuing indefinitely. 3102 BEGIN:VTIMEZONE 3103 TZID:US-Eastern 3104 LAST-MODIFIED:19870101T000000Z 3105 TZURL:http://zones.stds_r_us.net/tz/US-Eastern 3106 BEGIN:STANDARD 3107 DTSTART:19671029T020000 3108 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 3109 TZOFFSETFROM:-0400 3110 TZOFFSETTO:-0500 3111 TZNAME:EST 3112 END:STANDARD 3113 BEGIN:DAYLIGHT 3114 DTSTART:19870405T020000 3115 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4 3116 TZOFFSETFROM:-0500 3117 TZOFFSETTO:-0400 3118 TZNAME:EDT 3119 END:DAYLIGHT 3120 END:VTIMEZONE 3122 This is an example showing a fictitious set of rules for the Eastern 3123 United States, where the Daylight Time rule has an effective end date 3124 (i.e., after that date, Daylight Time is no longer observed). 3126 BEGIN:VTIMEZONE 3127 TZID:US--Fictitious-Eastern 3128 LAST-MODIFIED:19870101T000000Z 3129 BEGIN:STANDARD 3130 DTSTART:19671029T020000 3131 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 3132 TZOFFSETFROM:-0400 3133 TZOFFSETTO:-0500 3134 TZNAME:EST 3135 END:STANDARD 3136 BEGIN:DAYLIGHT 3137 DTSTART:19870405T020000 3138 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4;UNTIL=19980404T070000Z 3139 TZOFFSETFROM:-0500 3140 TZOFFSETTO:-0400 3141 TZNAME:EDT 3142 END:DAYLIGHT 3143 END:VTIMEZONE 3145 This is an example showing a fictitious set of rules for the Eastern 3146 United States, where the first Daylight Time rule has an effective 3147 end date. There is a second Daylight Time rule that picks up where 3148 the other left off. 3150 BEGIN:VTIMEZONE 3151 TZID:US--Fictitious-Eastern 3152 LAST-MODIFIED:19870101T000000Z 3153 BEGIN:STANDARD 3154 DTSTART:19671029T020000 3155 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 3156 TZOFFSETFROM:-0400 3157 TZOFFSETTO:-0500 3158 TZNAME:EST 3159 END:STANDARD 3160 BEGIN:DAYLIGHT 3161 DTSTART:19870405T020000 3162 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4;UNTIL=19980404T070000Z 3163 TZOFFSETFROM:-0500 3164 TZOFFSETTO:-0400 3165 TZNAME:EDT 3166 END:DAYLIGHT 3167 BEGIN:DAYLIGHT 3168 DTSTART:19990424T020000 3169 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=4 3170 TZOFFSETFROM:-0500 3171 TZOFFSETTO:-0400 3172 TZNAME:EDT 3173 END:DAYLIGHT 3174 END:VTIMEZONE 3176 4.6.6 Alarm Component 3178 Component Name: VALARM 3180 Purpose: Provide a grouping of component properties that define an 3181 alarm. 3183 Formal Definition: A "VALARM" calendar component is defined by the 3184 following notation: 3186 alarmc = "BEGIN" ":" "VALARM" CRLF 3187 (audioprop / dispprop / emailprop / procprop) 3188 "END" ":" "VALARM" CRLF 3190 audioprop = 2*( 3192 ; 'action' and 'trigger' are both REQUIRED, 3193 ; but MUST NOT occur more than once 3195 action / trigger / 3197 ; 'duration' and 'repeat' are both optional, 3198 ; and MUST NOT occur more than once each, 3199 ; but if one occurs, so MUST the other 3201 duration / repeat / 3203 ; the following is optional, 3204 ; but MUST NOT occur more than once 3206 attach / 3208 ; the following is optional, 3209 ; and MAY occur more than once 3211 x-prop 3213 ) 3214 dispprop = 3*( 3216 ; the following are all REQUIRED, 3217 ; but MUST NOT occur more than once 3219 action / description / trigger / 3221 ; 'duration' and 'repeat' are both optional, 3222 ; and MUST NOT occur more than once each, 3223 ; but if one occurs, so MUST the other 3225 duration / repeat / 3227 ; the following is optional, 3228 ; and MAY occur more than once 3230 *x-prop 3232 ) 3234 emailprop = 5*( 3236 ; the following are all REQUIRED, 3237 ; but MUST NOT occur more than once 3239 action / description / trigger / summary 3241 ; the following is REQUIRED, 3242 ; and MAY occur more than once 3244 attendee / 3246 ; 'duration' and 'repeat' are both optional, 3247 ; and MUST NOT occur more than once each, 3248 ; but if one occurs, so MUST the other 3250 duration / repeat / 3252 ; the following are optional, 3253 ; and MAY occur more than once 3255 attach / x-prop 3257 ) 3259 procprop = 3*( 3260 ; the following are all REQUIRED, 3261 ; but MUST NOT occur more than once 3263 action / attach / trigger / 3265 ; 'duration' and 'repeat' are both optional, 3266 ; and MUST NOT occur more than once each, 3267 ; but if one occurs, so MUST the other 3269 duration / repeat / 3271 ; 'description' is optional, 3272 ; and MUST NOT occur more than once 3274 description / 3276 ; the following is optional, 3277 ; and MAY occur more than once 3279 x-prop 3281 ) 3283 Description: A "VALARM" calendar component is a grouping of component 3284 properties that is a reminder or alarm for an event or a to-do. For 3285 example, it may be used to define a reminder for a pending event or 3286 an overdue to-do. 3288 The "VALARM" calendar component MUST include the "ACTION" and 3289 "TRIGGER" properties. The "ACTION" property further constrains the 3290 "VALARM" calendar component in the following ways: 3292 When the action is "AUDIO", the alarm can also include one and only 3293 one "ATTACH" property, which MUST point to a sound resource, which is 3294 rendered when the alarm is triggered. 3296 When the action is "DISPLAY", the alarm MUST also include a 3297 "DESCRIPTION" property, which contains the text to be displayed when 3298 the alarm is triggered. 3300 When the action is "EMAIL", the alarm MUST include a "DESCRIPTION" 3301 property, which contains the text to be used as the message body, a 3302 "SUMMARY" property, which contains the text to be used as the message 3303 subject, and one or more "ATTENDEE" properties, which contain the 3304 email address of attendees to receive the message. It can also 3305 include one or more "ATTACH" properties, which are intended to be 3306 sent as message attachments. When the alarm is triggered, the email 3307 message is sent. 3309 When the action is "PROCEDURE", the alarm MUST include one and only 3310 one "ATTACH" property, which MUST point to a procedure resource, 3311 which is invoked when the alarm is triggered. 3313 The "VALARM" calendar component MUST only appear within either a 3314 "VEVENT" or "VTODO" calendar component. "VALARM" calendar components 3315 cannot be nested. Multiple mutually independent "VALARM" calendar 3316 components can be specified for a single "VEVENT" or "VTODO" calendar 3317 component. 3319 The "TRIGGER" property specifies when the alarm will be triggered. 3320 The "TRIGGER" property specifies a duration prior to the start of an 3321 event or a to-do. The "TRIGGER" edge may be explicitly set to be 3322 relative to the "START" or "END" of the event or to-do with the 3323 "RELATED" parameter of the "TRIGGER" property. The "TRIGGER" property 3324 value type can alternatively be set to an absolute calendar date and 3325 time of day value. 3327 In an alarm set to trigger on the "START" of an event or to-do, the 3328 "DTSTART" property MUST be present in the associated event or to-do. 3329 In an alarm in a "VEVENT" calendar component set to trigger on the 3330 "END" of the event, either the "DTEND" property MUST be present, or 3331 the "DTSTART" and "DURATION" properties MUST both be present. In an 3332 alarm in a "VTODO" calendar component set to trigger on the "END" of 3333 the to-do, either the "DUE" property MUST be present, or the 3334 "DTSTART" and "DURATION" properties MUST both be present. 3336 The alarm can be defined such that it triggers repeatedly. A 3337 definition of an alarm with a repeating trigger MUST include both the 3338 "DURATION" and "REPEAT" properties. The "DURATION" property specifies 3339 the delay period, after which the alarm will repeat. The "REPEAT" 3340 property specifies the number of additional repetitions that the 3341 alarm will triggered. This repitition count is in addition to the 3342 initial triggering of the alarm. Both of these properties MUST be 3343 present in order to specify a repeating alarm. If one of these two 3344 properties is absent, then the alarm will not repeat beyond the 3345 initial trigger. 3347 The "ACTION" property is used within the "VALARM" calendar component 3348 to specify the type of action invoked when the alarm is triggered. 3349 The "VALARM" properties provide enough information for a specific 3350 action to be invoked. It is typically the responsibility of a 3351 "Calendar User Agent" (CUA) to deliver the alarm in the specified 3352 fashion. An "ACTION" property value of AUDIO specifies an alarm that 3353 causes a sound to be played to alert the user; DISPLAY specifies an 3354 alarm that causes a text message to be displayed to the user; EMAIL 3355 specifies an alarm that causes an electronic email message to be 3356 delivered to one or more email addresses; and PROCEDURE specifies an 3357 alarm that causes a procedure to be executed. The "ACTION" property 3358 MUST specify one and only one of these values. 3360 In an AUDIO alarm, if the optional "ATTACH" property is included, it 3361 MUST specify an audio sound resource. The intention is that the sound 3362 will be played as the alarm effect. If an "ATTACH" property is 3363 specified that does not refer to a sound resource, or if the 3364 specified sound resource cannot be rendered (because its format is 3365 unsupported, or because it cannot be retrieved), then the CUA or 3366 other entity responsible for playing the sound may choose a fallback 3367 action, such as playing a built-in default sound, or playing no sound 3368 at all. 3370 In a DISPLAY alarm, the intended alarm effect is for the text value 3371 of the "DESCRIPTION" property to be displayed to the user. 3373 In an EMAIL alarm, the intended alarm effect is for an email message 3374 to be composed and delivered to all the addresses specified by the 3375 "ATTENDEE" properties in the "VALARM" calendar component. The 3376 "DESCRIPTION" property of the "VALARM" calendar component MUST be 3377 used as the body text of the message, and the "SUMMARY" property MUST 3378 be used as the subject text. Any "ATTACH" properties in the "VALARM" 3379 calendar component SHOULD be sent as attachments to the message. 3381 In a PROCEDURE alarm, the "ATTACH" property in the "VALARM" calendar 3382 component MUST specify a procedure or program that is intended to be 3383 invoked as the alarm effect. If the procedure or program is in a 3384 format that cannot be rendered, then no procedure alarm will be 3385 invoked. If the "DESCRIPTION" property is present, its value 3386 specifies the argument string to be passed to the procedure or 3387 program. "Calendar User Agents" that receive an iCalendar object with 3388 this category of alarm, can disable or allow the "Calendar User" to 3389 disable, or otherwise ignore this type of alarm. While a very useful 3390 alarm capability, the PROCEDURE type of alarm SHOULD be treated by 3391 the "Calendar User Agent" as a potential security risk. 3393 Example: The following example is for a "VALARM" calendar component 3394 that specifies an audio alarm that will sound at a precise time and 3395 repeat 4 more times at 15 minute intervals: 3397 BEGIN:VALARM 3398 TRIGGER;VALUE=DATE-TIME:19970317T133000Z 3399 REPEAT:4 3400 DURATION:PT15M 3401 ACTION:AUDIO 3402 ATTACH;FMTTYPE=audio/basic:ftp://host.com/pub/sounds/bell-01.aud 3403 END:VALARM 3405 The following example is for a "VALARM" calendar component that 3406 specifies a display alarm that will trigger 30 minutes before the 3407 scheduled start of the event or the due date/time of the to-do it is 3408 associated with and will repeat 2 more times at 15 minute intervals: 3410 BEGIN:VALARM 3411 TRIGGER:-PT30M 3412 REPEAT:2 3413 DURATION:PT15M 3414 ACTION:DISPLAY 3415 DESCRIPTION:Breakfast meeting with executive\n 3416 team at 8:30 AM EST. 3417 END:VALARM 3419 The following example is for a "VALARM" calendar component that 3420 specifies an email alarm that will trigger 2 days before the 3421 scheduled due date/time of a to-do it is associated with. It does not 3422 repeat. The email has a subject, body and attachment link. 3424 BEGIN:VALARM 3425 TRIGGER:-P2D 3426 ACTION:EMAIL 3427 ATTENDEE:MAILTO:john_doe@host.com 3428 SUMMARY:*** REMINDER: SEND AGENDA FOR WEEKLY STAFF MEETING *** 3429 DESCRIPTION:A draft agenda needs to be sent out to the attendees 3430 to the weekly managers meeting (MGR-LIST). Attached is a 3431 pointer the document template for the agenda file. 3432 ATTACH;FMTTYPE=application/binary:http://host.com/templates/agen 3433 da.doc 3434 END:VALARM 3436 The following example is for a "VALARM" calendar component that 3437 specifies a procedural alarm that will trigger at a precise date/time 3438 and will repeat 23 more times at one hour intervals. The alarm will 3439 invoke a procedure file. 3441 BEGIN:VALARM 3442 TRIGGER;VALUE=DATE-TIME:19980101T050000Z 3443 REPEAT:23 3444 DURATION:PT1H 3445 ACTION:PROCEDURE 3446 ATTACH;FMTTYPE=application/binary:ftp://host.com/novo- 3447 procs/felizano.exe 3448 END:VALARM 3450 4.7 Calendar Properties 3452 The Calendar Properties are attributes that apply to the iCalendar 3453 object, as a whole. These properties do not appear within a calendar 3454 component. They SHOULD be specified after the "BEGIN:VCALENDAR" 3455 property and prior to any calendar component. 3457 4.7.1 Calendar Scale 3459 Property Name: CALSCALE 3461 Purpose: This property defines the calendar scale used for the 3462 calendar information specified in the iCalendar object. 3464 Value Type: TEXT 3466 Property Parameters: Non-standard property parameters can be 3467 specified on this property. 3469 Conformance: Property can be specified in an iCalendar object. The 3470 default value is "GREGORIAN". 3472 Description: This memo is based on the Gregorian calendar scale. The 3473 Gregorian calendar scale is assumed if this property is not specified 3474 in the iCalendar object. It is expected that other calendar scales 3475 will be defined in other specifications or by future versions of this 3476 memo. 3478 Format Definition: The property is defined by the following notation: 3480 calscale = "CALSCALE" calparam ":" calvalue CRLF 3482 calparam = *(";" xparam) 3484 calvalue = "GREGORIAN" / iana-token 3486 Example: The following is an example of this property: 3488 CALSCALE:GREGORIAN 3490 4.7.2 Method 3492 Property Name: METHOD 3494 Purpose: This property defines the iCalendar object method associated 3495 with the calendar object. 3497 Value Type: TEXT 3499 Property Parameters: Non-standard property parameters can be 3500 specified on this property. 3502 Conformance: The property can be specified in an iCalendar object. 3504 Description: When used in a MIME message entity, the value of this 3505 property MUST be the same as the Content-Type "method" parameter 3506 value. This property can only appear once within the iCalendar 3507 object. If either the "METHOD" property or the Content-Type "method" 3508 parameter is specified, then the other MUST also be specified. 3510 No methods are defined by this specification. This is the subject of 3511 other specifications, such as the iCalendar Transport-independent 3512 Interoperability Protocol (iTIP) defined by [ITIP]. 3514 If this property is not present in the iCalendar object, then a 3515 scheduling transaction MUST NOT be assumed. In such cases, the 3516 iCalendar object is merely being used to transport a snapshot of some 3517 calendar information; without the intention of conveying a scheduling 3518 semantic. 3520 Format Definition: The property is defined by the following notation: 3522 method = "METHOD" metparam ":" metvalue CRLF 3524 metparam = *(";" xparam) 3526 metvalue = iana-token 3527 Example: The following is a hypothetical example of this property to 3528 convey that the iCalendar object is a request for a meeting: 3530 METHOD:REQUEST 3532 4.7.3 Product Identifier 3534 Property Name: PRODID 3536 Purpose: This property specifies the identifier for the product that 3537 created the iCalendar object. 3539 Value Type: TEXT 3541 Property Parameters: Non-standard property parameters can be 3542 specified on this property. 3544 Conformance: The property MUST be specified once in an iCalendar 3545 object. 3547 Description: The vendor of the implementation SHOULD assure that this 3548 is a globally unique identifier; using some technique such as an FPI 3549 value, as defined in [ISO 9070]. 3551 This property SHOULD not be used to alter the interpretation of an 3552 iCalendar object beyond the semantics specified in this memo. For 3553 example, it is not to be used to further the understanding of non- 3554 standard properties. 3556 Format Definition: The property is defined by the following notation: 3558 prodid = "PRODID" pidparam ":" pidvalue CRLF 3560 pidparam = *(";" xparam) 3562 pidvalue = text 3563 ;Any text that describes the product and version 3564 ;and that is generally assured of being unique. 3566 Example: The following is an example of this property. It does not 3567 imply that English is the default language. 3569 PRODID:-//ABC Corporation//NONSGML My Product//EN 3571 4.7.4 Version 3573 Property Name: VERSION 3575 Purpose: This property specifies the identifier corresponding to the 3576 highest version number or the minimum and maximum range of the 3577 iCalendar specification that is required in order to interpret the 3578 iCalendar object. 3580 Value Type: TEXT 3581 Property Parameters: Non-standard property parameters can be 3582 specified on this property. 3584 Conformance: This property MUST be specified by an iCalendar object, 3585 but MUST only be specified once. 3587 Description: A value of "2.0" corresponds to this memo. 3589 Format Definition: The property is defined by the following notation: 3591 version = "VERSION" verparam ":" vervalue CRLF 3593 verparam = *(";" xparam) 3595 vervalue = "2.0" ;This memo 3596 / maxver 3597 / (minver ";" maxver) 3599 minver = 3600 ;Minimum iCalendar version needed to parse the iCalendar object 3602 maxver = 3603 ;Maximum iCalendar version needed to parse the iCalendar object 3605 Example: The following is an example of this property: 3607 VERSION:2.0 3609 4.8 Component Properties 3611 The following properties can appear within calendar components, as 3612 specified by each component property definition. 3614 4.8.1 Descriptive Component Properties 3616 The following properties specify descriptive information about 3617 calendar components. 3619 4.8.1.1 Attachment 3621 Property Name: ATTACH 3623 Purpose: The property provides the capability to associate a document 3624 object with a calendar component. 3626 Value Type: The default value type for this property is URI. The 3627 value type can also be set to BINARY to indicate inline binary 3628 encoded content information. 3630 Property Parameters: Non-standard, inline encoding, format type and 3631 value data type property parameters can be specified on this 3632 property. 3634 Conformance: The property can be specified in a "VEVENT", "VTODO", 3635 "VJOURNAL" or "VALARM" calendar components. 3637 Description: The property can be specified within "VEVENT", "VTODO", 3638 "VJOURNAL", or "VALARM" calendar components. This property can be 3639 specified multiple times within an iCalendar object. 3641 Format Definition: The property is defined by the following notation: 3643 attach = "ATTACH" attparam ":" uri CRLF 3645 attach =/ "ATTACH" attparam ";" "ENCODING" "=" "BASE64" 3646 ";" "VALUE" "=" "BINARY" ":" binary 3648 attparam = *( 3650 ; the following is optional, 3651 ; but MUST NOT occur more than once 3653 (";" fmttypeparam) / 3655 ; the following is optional, 3656 ; and MAY occur more than once 3658 (";" xparam) 3660 ) 3662 Example: The following are examples of this property: 3664 ATTACH:CID:jsmith.part3.960817T083000.xyzMail@host1.com 3666 ATTACH;FMTTYPE=application/postscript:ftp://xyzCorp.com/pub/ 3667 reports/r-960812.ps 3669 4.8.1.2 Categories 3671 Property Name: CATEGORIES 3673 Purpose: This property defines the categories for a calendar 3674 component. 3676 Value Type: TEXT 3678 Property Parameters: Non-standard and language property parameters 3679 can be specified on this property. 3681 Conformance: The property can be specified within "VEVENT", "VTODO" 3682 or "VJOURNAL" calendar components. 3684 Description: This property is used to specify categories or subtypes 3685 of the calendar component. The categories are useful in searching for 3686 a calendar component of a particular type and category. Within the 3687 "VEVENT", "VTODO" or "VJOURNAL" calendar components, more than one 3688 category can be specified as a list of categories separated by the 3689 COMMA character (US-ASCII decimal 44). 3691 Format Definition: The property is defined by the following notation: 3693 categories = "CATEGORIES" catparam ":" text *("," text) 3694 CRLF 3696 catparam = *( 3698 ; the following is optional, 3699 ; but MUST NOT occur more than once 3701 (";" languageparam ) / 3703 ; the following is optional, 3704 ; and MAY occur more than once 3706 (";" xparam) 3708 ) 3710 Example: The following are examples of this property: 3712 CATEGORIES:APPOINTMENT,EDUCATION 3714 CATEGORIES:MEETING 3716 4.8.1.3 Classification 3718 Property Name: CLASS 3720 Purpose: This property defines the access classification for a 3721 calendar component. 3723 Value Type: TEXT 3725 Property Parameters: Non-standard property parameters can be 3726 specified on this property. 3728 Conformance: The property can be specified once in a "VEVENT", 3729 "VTODO" or "VJOURNAL" calendar components. 3731 Description: An access classification is only one component of the 3732 general security system within a calendar application. It provides a 3733 method of capturing the scope of the access the calendar owner 3734 intends for information within an individual calendar entry. The 3735 access classification of an individual iCalendar component is useful 3736 when measured along with the other security components of a calendar 3737 system (e.g., calendar user authentication, authorization, access 3738 rights, access role, etc.). Hence, the semantics of the individual 3739 access classifications cannot be completely defined by this memo 3740 alone. Additionally, due to the "blind" nature of most exchange 3741 processes using this memo, these access classifications cannot serve 3742 as an enforcement statement for a system receiving an iCalendar 3743 object. Rather, they provide a method for capturing the intention of 3744 the calendar owner for the access to the calendar component. The 3745 [ICMS] provides a broader description of the security system within a 3746 calendar application. 3748 Format Definition: The property is defined by the following notation: 3750 class = "CLASS" classparam ":" classvalue CRLF 3752 classparam = *(";" xparam) 3754 classvalue = "PUBLIC" / "PRIVATE" / "CONFIDENTIAL" / iana-token 3755 / x-name 3756 ;Default is PUBLIC 3758 Example: The following is an example of this property: 3760 CLASS:PUBLIC 3762 4.8.1.4 Comment 3764 Property Name: COMMENT 3766 Purpose: This property specifies non-processing information intended 3767 to provide a comment to the calendar user. 3769 Value Type: TEXT 3771 Property Parameters: Non-standard, alternate text representation and 3772 language property parameters can be specified on this property. 3774 Conformance: This property can be specified in "VEVENT", "VTODO", 3775 "VJOURNAL", "VTIMEZONE" or "VFREEBUSY" calendar components. 3777 Description: The property can be specified multiple times. 3779 Format Definition: The property is defined by the following notation: 3781 comment = "COMMENT" commparam ":" text CRLF 3783 commparam = *( 3785 ; the following are optional, 3786 ; but MUST NOT occur more than once 3788 (";" altrepparam) / (";" languageparam) / 3790 ; the following is optional, 3791 ; and MAY occur more than once 3793 (";" xparam) 3795 ) 3796 Example: The following is an example of this property: 3798 COMMENT:The meeting really needs to include both ourselves 3799 and the customer. We can't hold this meeting without them. 3800 As a matter of fact\, the venue for the meeting ought to be at 3801 their site. - - John 3803 The data type for this property is TEXT. 3805 4.8.1.5 Description 3807 Property Name: DESCRIPTION 3809 Purpose: This property provides a more complete description of the 3810 calendar component, than that provided by the "SUMMARY" property. 3812 Value Type: TEXT 3814 Property Parameters: Non-standard, alternate text representation and 3815 language property parameters can be specified on this property. 3817 Conformance: The property can be specified in the "VEVENT", "VTODO", 3818 "VJOURNAL" or "VALARM" calendar components. The property can be 3819 specified multiple times only within a "VJOURNAL" calendar component. 3821 Description: This property is used in the "VEVENT" and "VTODO" to 3822 capture lengthy textual decriptions associated with the activity. 3824 This property is used in the "VJOURNAL" calendar component to capture 3825 one more textual journal entries. 3827 This property is used in the "VALARM" calendar component to capture 3828 the display text for a DISPLAY category of alarm, to capture the body 3829 text for an EMAIL category of alarm and to capture the argument 3830 string for a PROCEDURE category of alarm. 3832 Format Definition: The property is defined by the following notation: 3834 description = "DESCRIPTION" descparam ":" text CRLF 3836 descparam = *( 3838 ; the following are optional, 3839 ; but MUST NOT occur more than once 3841 (";" altrepparam) / (";" languageparam) / 3843 ; the following is optional, 3844 ; and MAY occur more than once 3846 (";" xparam) 3848 ) 3849 Example: The following is an example of the property with formatted 3850 line breaks in the property value: 3852 DESCRIPTION:Meeting to provide technical review for "Phoenix" 3853 design.\n Happy Face Conference Room. Phoenix design team 3854 MUST attend this meeting.\n RSVP to team leader. 3856 The following is an example of the property with folding of long 3857 lines: 3859 DESCRIPTION:Last draft of the new novel is to be completed 3860 for the editor's proof today. 3862 4.8.1.6 Geographic Position 3864 Property Name: GEO 3866 Purpose: This property specifies information related to the global 3867 position for the activity specified by a calendar component. 3869 Value Type: FLOAT. The value MUST be two SEMICOLON separated FLOAT 3870 values. 3872 Property Parameters: Non-standard property parameters can be 3873 specified on this property. 3875 Conformance: This property can be specified in "VEVENT" or "VTODO" 3876 calendar components.. 3878 Description: The property value specifies latitude and longitude, in 3879 that order (i.e., "LAT LON" ordering). The longitude represents the 3880 location east or west of the prime meridian as a positive or negative 3881 real number, respectively. The longitude and latitude values MAY be 3882 specified up to six decimal places, which will allow for accuracy to 3883 within one meter of geographical position. Receiving applications 3884 MUST accept values of this precision and MAY truncate values of 3885 greater precision. 3887 Values for latitude and longitude shall be expressed as decimal 3888 fractions of degrees. Whole degrees of latitude shall be represented 3889 by a two-digit decimal number ranging from 0 through 90. Whole 3890 degrees of longitude shall be represented by a decimal number ranging 3891 from 0 through 180. When a decimal fraction of a degree is specified, 3892 it shall be separated from the whole number of degrees by a decimal 3893 point. 3895 Latitudes north of the equator shall be specified by a plus sign (+), 3896 or by the absence of a minus sign (-), preceding the digits 3897 designating degrees. Latitudes south of the Equator shall be 3898 designated by a minus sign (-) preceding the digits designating 3899 degrees. A point on the Equator shall be assigned to the Northern 3900 Hemisphere. 3902 Longitudes east of the prime meridian shall be specified by a plus 3903 sign (+), or by the absence of a minus sign (-), preceding the digits 3904 designating degrees. Longitudes west of the meridian shall be 3905 designated by minus sign (-) preceding the digits designating 3906 degrees. A point on the prime meridian shall be assigned to the 3907 Eastern Hemisphere. A point on the 180th meridian shall be assigned 3908 to the Western Hemisphere. One exception to this last convention is 3909 permitted. For the special condition of describing a band of latitude 3910 around the earth, the East Bounding Coordinate data element shall be 3911 assigned the value +180 (180) degrees. 3913 Any spatial address with a latitude of +90 (90) or -90 degrees will 3914 specify the position at the North or South Pole, respectively. The 3915 component for longitude may have any legal value. 3917 With the exception of the special condition described above, this 3918 form is specified in Department of Commerce, 1986, Representation of 3919 geographic point locations for information interchange (Federal 3920 Information Processing Standard 70-1): Washington, Department of 3921 Commerce, National Institute of Standards and Technology. 3923 The simple formula for converting degrees-minutes-seconds into 3924 decimal degrees is: 3926 decimal = degrees + minutes/60 + seconds/3600. 3928 Format Definition: The property is defined by the following notation: 3930 geo = "GEO" geoparam ":" geovalue CRLF 3932 geoparam = *(";" xparam) 3934 geovalue = float ";" float 3935 ;Latitude and Longitude components 3937 Example: The following is an example of this property: 3939 GEO:37.386013;-122.082932 3941 4.8.1.7 Location 3943 Property Name: LOCATION 3945 Purpose: The property defines the intended venue for the activity 3946 defined by a calendar component. 3948 Value Type: TEXT 3950 Property Parameters: Non-standard, alternate text representation and 3951 language property parameters can be specified on this property. 3953 Conformance: This property can be specified in "VEVENT" or "VTODO" 3954 calendar component. 3956 Description: Specific venues such as conference or meeting rooms may 3957 be explicitly specified using this property. An alternate 3958 representation may be specified that is a URI that points to 3959 directory information with more structured specification of the 3960 location. For example, the alternate representation may specify 3961 either an LDAP URI pointing to an LDAP server entry or a CID URI 3962 pointing to a MIME body part containing a vCard for the location. 3964 Format Definition: The property is defined by the following notation: 3966 location = "LOCATION locparam ":" text CRLF 3968 locparam = *( 3970 ; the following are optional, 3971 ; but MUST NOT occur more than once 3973 (";" altrepparam) / (";" languageparam) / 3975 ; the following is optional, 3976 ; and MAY occur more than once 3978 (";" xparam) 3980 ) 3982 Example: The following are some examples of this property: 3984 LOCATION:Conference Room - F123, Bldg. 002 3986 LOCATION;ALTREP="http://xyzcorp.com/conf-rooms/f123.vcf": 3987 Conference Room - F123, Bldg. 002 3989 4.8.1.8 Percent Complete 3991 Property Name: PERCENT-COMPLETE 3993 Purpose: This property is used by an assignee or delegatee of a to-do 3994 to convey the percent completion of a to-do to the Organizer. 3996 Value Type: INTEGER 3998 Property Parameters: Non-standard property parameters can be 3999 specified on this property. 4001 Conformance: This property can be specified in a "VTODO" calendar 4002 component. 4004 Description: The property value is a positive integer between zero 4005 and one hundred. A value of "0" indicates the to-do has not yet been 4006 started. A value of "100" indicates that the to-do has been 4007 completed. Integer values in between indicate the percent partially 4008 complete. 4010 When a to-do is assigned to multiple individuals, the property value 4011 indicates the percent complete for that portion of the to-do assigned 4012 to the assignee or delegatee. For example, if a to-do is assigned to 4013 both individuals "A" and "B". A reply from "A" with a percent 4014 complete of "70" indicates that "A" has completed 70% of the to-do 4015 assigned to them. A reply from "B" with a percent complete of "50" 4016 indicates "B" has completed 50% of the to-do assigned to them. 4018 Format Definition: The property is defined by the following notation: 4020 percent = "PERCENT-COMPLETE" pctparam ":" integer CRLF 4022 pctparam = *(";" xparam) 4024 Example: The following is an example of this property to show 39% 4025 completion: 4027 PERCENT-COMPLETE:39 4029 4.8.1.9 Priority 4031 Property Name: PRIORITY 4033 Purpose: The property defines the relative priority for a calendar 4034 component. 4036 Value Type: INTEGER 4038 Property Parameters: Non-standard property parameters can be 4039 specified on this property. 4041 Conformance: The property can be specified in a "VEVENT" or "VTODO" 4042 calendar component. 4044 Description: The priority is specified as an integer in the range 4045 zero to nine. A value of zero (US-ASCII decimal 48) specifies an 4046 undefined priority. A value of one (US-ASCII decimal 49) is the 4047 highest priority. A value of two (US-ASCII decimal 50) is the second 4048 highest priority. Subsequent numbers specify a decreasing ordinal 4049 priority. A value of nine (US-ASCII decimal 58) is the lowest 4050 priority. 4052 A CUA with a three-level priority scheme of "HIGH", "MEDIUM" and 4053 "LOW" is mapped into this property such that a property value in the 4054 range of one (US-ASCII decimal 49) to four (US-ASCII decimal 52) 4055 specifies "HIGH" priority. A value of five (US-ASCII decimal 53) is 4056 the normal or "MEDIUM" priority. A value in the range of six (US- 4057 ASCII decimal 54) to nine (US-ASCII decimal 58) is "LOW" priority. 4059 A CUA with a priority schema of "A1", "A2", "A3", "B1", "B2", ..., 4060 "C3" is mapped into this property such that a property value of one 4061 (US-ASCII decimal 49) specifies "A1", a property value of two (US- 4062 ASCII decimal 50) specifies "A2", a property value of three (US-ASCII 4063 decimal 51) specifies "A3", and so forth up to a property value of 9 4064 (US-ASCII decimal 58) specifies "C3". 4066 Other integer values are reserved for future use. 4068 Within a "VEVENT" calendar component, this property specifies a 4069 priority for the event. This property may be useful when more than 4070 one event is scheduled for a given time period. 4072 Within a "VTODO" calendar component, this property specified a 4073 priority for the to-do. This property is useful in prioritizing 4074 multiple action items for a given time period. 4076 Format Definition: The property is specified by the following 4077 notation: 4079 priority = "PRIORITY" prioparam ":" privalue CRLF 4080 ;Default is zero 4082 prioparam = *(";" xparam) 4084 privalue = integer ;Must be in the range [0..9] 4085 ; All other values are reserved for future use 4087 The following is an example of a property with the highest priority: 4089 PRIORITY:1 4091 The following is an example of a property with a next highest 4092 priority: 4094 PRIORITY:2 4096 Example: The following is an example of a property with no priority. 4097 This is equivalent to not specifying the "PRIORITY" property: 4099 PRIORITY:0 4101 4.8.1.10 Resources 4103 Property Name: RESOURCES 4105 Purpose: This property defines the equipment or resources anticipated 4106 for an activity specified by a calendar entity.. 4108 Value Type: TEXT 4110 Property Parameters: Non-standard, alternate text representation and 4111 language property parameters can be specified on this property. 4113 Conformance: This property can be specified in "VEVENT" or "VTODO" 4114 calendar component. 4116 Description: The property value is an arbitrary text. More than one 4117 resource can be specified as a list of resources separated by the 4118 COMMA character (US-ASCII decimal 44). 4120 Format Definition: The property is defined by the following notation: 4122 resources = "RESOURCES" resrcparam ":" text *("," text) CRLF 4124 resrcparam = *( 4126 ; the following are optional, 4127 ; but MUST NOT occur more than once 4129 (";" altrepparam) / (";" languageparam) / 4131 ; the following is optional, 4132 ; and MAY occur more than once 4134 (";" xparam) 4136 ) 4138 Example: The following is an example of this property: 4140 RESOURCES:EASEL,PROJECTOR,VCR 4142 RESOURCES;LANGUAGE=fr:1 raton-laveur 4144 4.8.1.11 Status 4146 Property Name: STATUS 4148 Purpose: This property defines the overall status or confirmation for 4149 the calendar component. 4151 Value Type: TEXT 4153 Property Parameters: Non-standard property parameters can be 4154 specified on this property. 4156 Conformance: This property can be specified in "VEVENT", "VTODO" or 4157 "VJOURNAL" calendar components. 4159 Description: In a group scheduled calendar component, the property is 4160 used by the "Organizer" to provide a confirmation of the event to the 4161 "Attendees". For example in a "VEVENT" calendar component, the 4162 "Organizer" can indicate that a meeting is tentative, confirmed or 4163 cancelled. In a "VTODO" calendar component, the "Organizer" can 4164 indicate that an action item needs action, is completed, is in 4165 process or being worked on, or has been cancelled. In a "VJOURNAL" 4166 calendar component, the "Organizer" can indicate that a journal entry 4167 is draft, final or has been cancelled or removed. 4169 Format Definition: The property is defined by the following notation: 4171 status = "STATUS" statparam] ":" statvalue CRLF 4173 statparam = *(";" xparam) 4175 statvalue = "TENTATIVE" ;Indicates event is 4176 ;tentative. 4177 / "CONFIRMED" ;Indicates event is 4178 ;definite. 4179 / "CANCELLED" ;Indicates event was 4180 ;cancelled. 4181 ;Status values for a "VEVENT" 4183 statvalue =/ "NEEDS-ACTION" ;Indicates to-do needs action. 4184 / "COMPLETED" ;Indicates to-do completed. 4185 / "IN-PROCESS" ;Indicates to-do in process of 4186 / "CANCELLED" ;Indicates to-do was cancelled. 4187 ;Status values for "VTODO". 4189 statvalue =/ "DRAFT" ;Indicates journal is draft. 4190 / "FINAL" ;Indicates journal is final. 4191 / "CANCELLED" ;Indicates journal is removed. 4192 ;Status values for "VJOURNAL". 4194 Example: The following is an example of this property for a "VEVENT" 4195 calendar component: 4197 STATUS:TENTATIVE 4199 The following is an example of this property for a "VTODO" calendar 4200 component: 4202 STATUS:NEEDS-ACTION 4204 The following is an example of this property for a "VJOURNAL" 4205 calendar component: 4207 STATUS:DRAFT 4209 4.8.1.12 Summary 4211 Property Name: SUMMARY 4213 Purpose: This property defines a short summary or subject for the 4214 calendar component. 4216 Value Type: TEXT 4218 Property Parameters: Non-standard, alternate text representation and 4219 language property parameters can be specified on this property. 4221 Conformance: The property can be specified in "VEVENT", "VTODO", 4222 "VJOURNAL" or "VALARM" calendar components. 4224 Description: This property is used in the "VEVENT", "VTODO" and 4225 "VJOURNAL" calendar components to capture a short, one line summary 4226 about the activity or journal entry. 4228 This property is used in the "VALARM" calendar component to capture 4229 the subject of an EMAIL category of alarm. 4231 Format Definition: The property is defined by the following notation: 4233 summary = "SUMMARY" summparam ":" text CRLF 4235 summparam = *( 4237 ; the following are optional, 4238 ; but MUST NOT occur more than once 4240 (";" altrepparam) / (";" languageparam) / 4242 ; the following is optional, 4243 ; and MAY occur more than once 4245 (";" xparam) 4247 ) 4249 Example: The following is an example of this property: 4251 SUMMARY:Department Party 4253 4.8.2 Date and Time Component Properties 4255 The following properties specify date and time related information in 4256 calendar components. 4258 4.8.2.1 Date/Time Completed 4260 Property Name: COMPLETED 4262 Purpose: This property defines the date and time that a to-do was 4263 actually completed. 4265 Value Type: DATE-TIME 4267 Property Parameters: Non-standard property parameters can be 4268 specified on this property. 4270 Conformance: The property can be specified in a "VTODO" calendar 4271 component. 4273 Description: The date and time MUST be in a UTC format. 4275 Format Definition: The property is defined by the following notation: 4277 completed = "COMPLETED" compparam ":" date-time CRLF 4278 compparam = *(";" xparam) 4280 Example: The following is an example of this property: 4282 COMPLETED:19960401T235959Z 4284 4.8.2.2 Date/Time End 4286 Property Name: DTEND 4288 Purpose: This property specifies the date and time that a calendar 4289 component ends. 4291 Value Type: The default value type is DATE-TIME. The value type can 4292 be set to a DATE value type. 4294 Property Parameters: Non-standard, value data type, time zone 4295 identifier property parameters can be specified on this property. 4297 Conformance: This property can be specified in "VEVENT" or 4298 "VFREEBUSY" calendar components. 4300 Description: Within the "VEVENT" calendar component, this property 4301 defines the date and time by which the event ends. The value MUST be 4302 later in time than the value of the "DTSTART" property. 4304 Within the "VFREEBUSY" calendar component, this property defines the 4305 end date and time for the free or busy time information. The time 4306 MUST be specified in the UTC time format. The value MUST be later in 4307 time than the value of the "DTSTART" property. 4309 Format Definition: The property is defined by the following notation: 4311 dtend = "DTEND" dtendparam":" dtendval CRLF 4313 dtendparam = *( 4315 ; the following are optional, 4316 ; but MUST NOT occur more than once 4318 (";" "VALUE" "=" ("DATE-TIME" / "DATE")) / 4319 (";" tzidparam) / 4321 ; the following is optional, 4322 ; and MAY occur more than once 4324 (";" xparam) 4326 ) 4328 dtendval = date-time / date 4329 ;Value MUST match value type 4330 Example: The following is an example of this property: 4332 DTEND:19960401T235959Z 4334 DTEND;VALUE=DATE:19980704 4336 4.8.2.3 Date/Time Due 4338 Property Name: DUE 4340 Purpose: This property defines the date and time that a to-do is 4341 expected to be completed. 4343 Value Type: The default value type is DATE-TIME. The value type can 4344 be set to a DATE value type. 4346 Property Parameters: Non-standard, value data type, time zone 4347 identifier property parameters can be specified on this property. 4349 Conformance: The property can be specified once in a "VTODO" calendar 4350 component. 4352 Description: The value MUST be a date/time equal to or after the 4353 DTSTART value, if specified. 4355 Format Definition: The property is defined by the following notation: 4357 due = "DUE" dueparam":" dueval CRLF 4359 dueparam = *( 4361 ; the following are optional, 4362 ; but MUST NOT occur more than once 4364 (";" "VALUE" "=" ("DATE-TIME" / "DATE")) / 4365 (";" tzidparam) / 4367 ; the following is optional, 4368 ; and MAY occur more than once 4370 *(";" xparam) 4372 ) 4374 dueval = date-time / date 4375 ;Value MUST match value type 4377 Example: The following is an example of this property: 4379 DUE:19980430T235959Z 4380 4.8.2.4 Date/Time Start 4382 Property Name: DTSTART 4384 Purpose: This property specifies when the calendar component begins. 4386 Value Type: The default value type is DATE-TIME. The time value MUST 4387 be one of the forms defined for the DATE-TIME value type. The value 4388 type can be set to a DATE value type. 4390 Property Parameters: Non-standard, value data type, time zone 4391 identifier property parameters can be specified on this property. 4393 Conformance: This property can be specified in the "VEVENT", "VTODO", 4394 "VFREEBUSY", or "VTIMEZONE" calendar components. 4396 Description: Within the "VEVENT" calendar component, this property 4397 defines the start date and time for the event. The property is 4398 REQUIRED in "VEVENT" calendar components. Events can have a start 4399 date/time but no end date/time. In that case, the event does not take 4400 up any time. 4402 Within the "VFREEBUSY" calendar component, this property defines the 4403 start date and time for the free or busy time information. The time 4404 MUST be specified in UTC time. 4406 Within the "VTIMEZONE" calendar component, this property defines the 4407 effective start date and time for a time zone specification. This 4408 property is REQUIRED within each STANDARD and DAYLIGHT part included 4409 in "VTIMEZONE" calendar components and MUST be specified as a local 4410 DATE-TIME without the "TZID" property parameter. 4412 Format Definition: The property is defined by the following notation: 4414 dtstart = "DTSTART" dtstparam ":" dtstval CRLF 4416 dtstparam = *( 4418 ; the following are optional, 4419 ; but MUST NOT occur more than once 4421 (";" "VALUE" "=" ("DATE-TIME" / "DATE")) / 4422 (";" tzidparam) / 4424 ; the following is optional, 4425 ; and MAY occur more than once 4427 *(";" xparam) 4429 ) 4430 dtstval = date-time / date 4431 ;Value MUST match value type 4433 Example: The following is an example of this property: 4435 DTSTART:19980118T073000Z 4437 4.8.2.5 Duration 4439 Property Name: DURATION 4441 Purpose: The property specifies a positive duration of time . 4443 Value Type: DURATION 4445 Property Parameters: Non-standard property parameters can be 4446 specified on this property. 4448 Conformance: The property can be specified in "VEVENT", "VTODO", 4449 "VFREEBUSY" or "VALARM" calendar components. 4451 Description: In a "VEVENT" calendar component the property may be 4452 used to specify a duration of the event, instead of an explicit end 4453 date/time. In a "VTODO" calendar component the property may be used 4454 to specify a duration for the to-do, instead of an explicit due 4455 date/time. In a "VFREEBUSY" calendar component the property may be 4456 used to specify the interval of free time being requested. In a 4457 "VALARM" calendar component the property may be used to specify the 4458 delay period prior to repeating an alarm. 4460 Format Definition: The property is defined by the following notation: 4462 duration = "DURATION" durparam ":" dur-value CRLF 4463 ;consisting of a positive duration of time. 4465 durparam = *(";" xparam) 4467 Example: The following is an example of this property that specifies 4468 an interval of time of 1 hour and zero minutes and zero seconds: 4470 DURATION:PT1H0M0S 4472 The following is an example of this property that specifies an 4473 interval of time of 15 minutes. 4475 DURATION:PT15M 4477 4.8.2.6 Free/Busy Time 4479 Property Name: FREEBUSY 4481 Purpose: The property defines one or more free or busy time 4482 intervals. 4484 Value Type: PERIOD. The date and time values MUST be in an UTC time 4485 format. 4487 Property Parameters: Non-standard or free/busy time type property 4488 parameters can be specified on this property. 4490 Conformance: The property can be specified in a "VFREEBUSY" calendar 4491 component. 4493 Property Parameter: "FBTYPE" and non-standard parameters can be 4494 specified on this property. 4496 Description: These time periods can be specified as either a start 4497 and end date-time or a start date-time and duration. The date and 4498 time MUST be a UTC time format. 4500 "FREEBUSY" properties within the "VFREEBUSY" calendar component 4501 SHOULD be sorted in ascending order, based on start time and then end 4502 time, with the earliest periods first. 4504 The "FREEBUSY" property can specify more than one value, separated by 4505 the COMMA character (US-ASCII decimal 44). In such cases, the 4506 "FREEBUSY" property values SHOULD all be of the same "FBTYPE" 4507 property parameter type (e.g., all values of a particular "FBTYPE" 4508 listed together in a single property). 4510 Format Definition: The property is defined by the following notation: 4512 freebusy = "FREEBUSY" fbparam ":" fbvalue 4513 CRLF 4515 fbparam = *( 4517 ; the following is optional, 4518 ; but MUST NOT occur more than once 4520 (";" fbtypeparam) / 4522 ; the following is optional, 4523 ; and MAY occur more than once 4525 (";" xparam) 4527 ) 4529 fbvalue = period *["," period] 4530 ;Time value MUST be in the UTC time format. 4532 Example: The following are some examples of this property: 4534 FREEBUSY;FBTYPE=BUSY-UNAVAILABLE:19970308T160000Z/PT8H30M 4536 FREEBUSY;FBTYPE=FREE:19970308T160000Z/PT3H,19970308T200000Z/PT1H 4537 FREEBUSY;FBTYPE=FREE:19970308T160000Z/PT3H,19970308T200000Z/PT1H, 4538 19970308T230000Z/19970309T000000Z 4540 4.8.2.7 Time Transparency 4542 Property Name: TRANSP 4544 Purpose: This property defines whether an event is transparent or not 4545 to busy time searches. 4547 Value Type: TEXT 4549 Property Parameters: Non-standard property parameters can be 4550 specified on this property. 4552 Conformance: This property can be specified once in a "VEVENT" 4553 calendar component. 4555 Description: Time Transparency is the characteristic of an event that 4556 determines whether it appears to consume time on a calendar. Events 4557 that consume actual time for the individual or resource associated 4558 with the calendar SHOULD be recorded as OPAQUE, allowing them to be 4559 detected by free-busy time searches. Other events, which do not take 4560 up the individual's (or resource's) time SHOULD be recorded as 4561 TRANSPARENT, making them invisible to free-busy time searches. 4563 Format Definition: The property is specified by the following 4564 notation: 4566 transp = "TRANSP" tranparam ":" transvalue CRLF 4568 tranparam = *(";" xparam) 4570 transvalue = "OPAQUE" ;Blocks or opaque on busy time searches. 4571 / "TRANSPARENT" ;Transparent on busy time searches. 4572 ;Default value is OPAQUE 4574 Example: The following is an example of this property for an event 4575 that is transparent or does not block on free/busy time searches: 4577 TRANSP:TRANSPARENT 4579 The following is an example of this property for an event that is 4580 opaque or blocks on free/busy time searches: 4582 TRANSP:OPAQUE 4584 4.8.3 Time Zone Component Properties 4586 The following properties specify time zone information in calendar 4587 components. 4589 4.8.3.1 Time Zone Identifier 4591 Property Name: TZID 4593 Purpose: This property specifies the text value that uniquely 4594 identifies the "VTIMEZONE" calendar component. 4596 Value Type: TEXT 4598 Property Parameters: Non-standard property parameters can be 4599 specified on this property. 4601 Conformance: This property MUST be specified in a "VTIMEZONE" 4602 calendar component. 4604 Description: This is the label by which a time zone calendar 4605 component is referenced by any iCalendar properties whose data type 4606 is either DATE-TIME or TIME and not intended to specify a UTC or a 4607 "floating" time. The presence of the SOLIDUS character (US-ASCII 4608 decimal 47) as a prefix, indicates that this TZID represents an 4609 unique ID in a globally defined time zone registry (when such 4610 registry is defined). 4612 Note: This document does not define a naming convention for time 4613 zone identifiers. Implementers may want to use the naming 4614 conventions defined in existing time zone specifications such as 4615 the public-domain Olson database [TZ]. The specification of 4616 globally unique time zone identifiers is not addressed by this 4617 document and is left for future study. 4619 Format Definition: This property is defined by the following 4620 notation: 4622 tzid = "TZID" tzidpropparam ":" [tzidprefix] text CRLF 4624 tzidpropparam = *(";" xparam) 4626 ;tzidprefix = "/" 4627 ; Defined previously. Just listed here for reader convenience. 4629 Example: The following are examples of non-globally unique time zone 4630 identifiers: 4632 TZID:US-Eastern 4634 TZID:California-Los_Angeles 4636 The following is an example of a fictitious globally unique time zone 4637 identifier: 4639 TZID:/US-New_York-New_York 4640 4.8.3.2 Time Zone Name 4642 Property Name: TZNAME 4644 Purpose: This property specifies the customary designation for a time 4645 zone description. 4647 Value Type: TEXT 4649 Property Parameters: Non-standard and language property parameters 4650 can be specified on this property. 4652 Conformance: This property can be specified in a "VTIMEZONE" calendar 4653 component. 4655 Description: This property may be specified in multiple languages; in 4656 order to provide for different language requirements. 4658 Format Definition: This property is defined by the following 4659 notation: 4661 tzname = "TZNAME" tznparam ":" text CRLF 4663 tznparam = *( 4665 ; the following is optional, 4666 ; but MUST NOT occur more than once 4668 (";" languageparam) / 4670 ; the following is optional, 4671 ; and MAY occur more than once 4673 (";" xparam) 4675 ) 4677 Example: The following are example of this property: 4679 TZNAME:EST 4681 The following is an example of this property when two different 4682 languages for the time zone name are specified: 4684 TZNAME;LANGUAGE=en:EST 4685 TZNAME;LANGUAGE=fr-CA:HNE 4687 4.8.3.3 Time Zone Offset From 4689 Property Name: TZOFFSETFROM 4691 Purpose: This property specifies the offset which is in use prior to 4692 this time zone observance. 4694 Value Type: UTC-OFFSET 4696 Property Parameters: Non-standard property parameters can be 4697 specified on this property. 4699 Conformance: This property MUST be specified in a "VTIMEZONE" 4700 calendar component. 4702 Description: This property specifies the offset which is in use prior 4703 to this time observance. It is used to calculate the absolute time at 4704 which the transition to a given observance takes place. This property 4705 MUST only be specified in a "VTIMEZONE" calendar component. A 4706 "VTIMEZONE" calendar component MUST include this property. The 4707 property value is a signed numeric indicating the number of hours and 4708 possibly minutes from UTC. Positive numbers represent time zones east 4709 of the prime meridian, or ahead of UTC. Negative numbers represent 4710 time zones west of the prime meridian, or behind UTC. 4712 Format Definition: The property is defined by the following notation: 4714 tzoffsetfrom = "TZOFFSETFROM" frmparam ":" utc-offset 4715 CRLF 4717 frmparam = *(";" xparam) 4719 Example: The following are examples of this property: 4721 TZOFFSETFROM:-0500 4723 TZOFFSETFROM:+1345 4725 4.8.3.4 Time Zone Offset To 4727 Property Name: TZOFFSETTO 4729 Purpose: This property specifies the offset which is in use in this 4730 time zone observance. 4732 Value Type: UTC-OFFSET 4734 Property Parameters: Non-standard property parameters can be 4735 specified on this property. 4737 Conformance: This property MUST be specified in a "VTIMEZONE" 4738 calendar component. 4740 Description: This property specifies the offset which is in use in 4741 this time zone observance. It is used to calculate the absolute time 4742 for the new observance. The property value is a signed numeric 4743 indicating the number of hours and possibly minutes from UTC. 4744 Positive numbers represent time zones east of the prime meridian, or 4745 ahead of UTC. Negative numbers represent time zones west of the prime 4746 meridian, or behind UTC. 4748 Format Definition: The property is defined by the following notation: 4750 tzoffsetto = "TZOFFSETTO" toparam ":" utc-offset CRLF 4752 toparam = *(";" xparam) 4754 Example: The following are examples of this property: 4756 TZOFFSETTO:-0400 4758 TZOFFSETTO:+1245 4760 4.8.3.5 Time Zone URL 4762 Property Name: TZURL 4764 Purpose: The TZURL provides a means for a VTIMEZONE component to 4765 point to a network location that can be used to retrieve an up-to- 4766 date version of itself. 4768 Value Type: URI 4770 Property Parameters: Non-standard property parameters can be 4771 specified on this property. 4773 Conformance: This property can be specified in a "VTIMEZONE" calendar 4774 component. 4776 Description: The TZURL provides a means for a VTIMEZONE component to 4777 point to a network location that can be used to retrieve an up-to- 4778 date version of itself. This provides a hook to handle changes 4779 government bodies impose upon time zone definitions. Retrieval of 4780 this resource results in an iCalendar object containing a single 4781 VTIMEZONE component and a METHOD property set to PUBLISH. 4783 Format Definition: The property is defined by the following notation: 4785 tzurl = "TZURL" tzurlparam ":" uri CRLF 4787 tzurlparam = *(";" xparam) 4789 Example: The following is an example of this property: 4791 TZURL:http://timezones.r.us.net/tz/US-California-Los_Angeles 4793 4.8.4 Relationship Component Properties 4795 The following properties specify relationship information in calendar 4796 components. 4798 4.8.4.1 Attendee 4800 Property Name: ATTENDEE 4801 Purpose: The property defines an "Attendee" within a calendar 4802 component. 4804 Value Type: CAL-ADDRESS 4806 Property Parameters: Non-standard, language, calendar user type, 4807 group or list membership, participation role, participation status, 4808 RSVP expectation, delegatee, delegator, sent by, common name or 4809 directory entry reference property parameters can be specified on 4810 this property. 4812 Conformance: This property MUST be specified in an iCalendar object 4813 that specifies a group scheduled calendar entity. This property MUST 4814 NOT be specified in an iCalendar object when publishing the calendar 4815 information (e.g., NOT in an iCalendar object that specifies the 4816 publication of a calendar user's busy time, event, to-do or journal). 4817 This property is not specified in an iCalendar object that specifies 4818 only a time zone definition or that defines calendar entities that 4819 are not group scheduled entities, but are entities only on a single 4820 user's calendar. 4822 Description: The property MUST only be specified within calendar 4823 components to specify participants, non-participants and the chair of 4824 a group scheduled calendar entity. The property is specified within 4825 an "EMAIL" category of the "VALARM" calendar component to specify an 4826 email address that is to receive the email type of iCalendar alarm. 4828 The property parameter CN is for the common or displayable name 4829 associated with the calendar address; ROLE, for the intended role 4830 that the attendee will have in the calendar component; PARTSTAT, for 4831 the status of the attendee's participation; RSVP, for indicating 4832 whether the favor of a reply is requested; CUTYPE, to indicate the 4833 type of calendar user; MEMBER, to indicate the groups that the 4834 attendee belongs to; DELEGATED-TO, to indicate the calendar users 4835 that the original request was delegated to; and DELEGATED-FROM, to 4836 indicate whom the request was delegated from; SENT-BY, to indicate 4837 whom is acting on behalf of the ATTENDEE; and DIR, to indicate the 4838 URI that points to the directory information corresponding to the 4839 attendee. These property parameters can be specified on an "ATTENDEE" 4840 property in either a "VEVENT", "VTODO" or "VJOURNAL" calendar 4841 component. They MUST not be specified in an "ATTENDEE" property in a 4842 "VFREEBUSY" or "VALARM" calendar component. If the LANGUAGE property 4843 parameter is specified, the identified language applies to the CN 4844 parameter. 4846 A recipient delegated a request MUST inherit the RSVP and ROLE values 4847 from the attendee that delegated the request to them. 4849 Multiple attendees can be specified by including multiple "ATTENDEE" 4850 properties within the calendar component. 4852 Format Definition: The property is defined by the following notation: 4854 attendee = "ATTENDEE" attparam ":" cal-address CRLF 4855 attparam = *( 4857 ; the following are optional, 4858 ; but MUST NOT occur more than once 4860 (";" cutypeparam) / (";"memberparam) / 4861 (";" roleparam) / (";" partstatparam) / 4862 (";" rsvpparam) / (";" deltoparam) / 4863 (";" delfromparam) / (";" sentbyparam) / 4864 (";"cnparam) / (";" dirparam) / 4865 (";" languageparam) / 4867 ; the following is optional, 4868 ; and MAY occur more than once 4870 (";" xparam) 4872 ) 4874 Example: The following are examples of this property's use for a to- 4875 do: 4877 ORGANIZER:MAILTO:jsmith@host1.com 4878 ATTENDEE;MEMBER="MAILTO:DEV-GROUP@host2.com": 4879 MAILTO:joecool@host2.com 4880 ATTENDEE;DELEGATED-FROM="MAILTO:immud@host3.com": 4881 MAILTO:ildoit@host1.com 4883 The following is an example of this property used for specifying 4884 multiple attendees to an event: 4886 ORGANIZER:MAILTO:jsmith@host1.com 4887 ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=TENTATIVE;CN=Henry Cabot 4888 :MAILTO:hcabot@host2.com 4889 ATTENDEE;ROLE=REQ-PARTICIPANT;DELEGATED-FROM="MAILTO:bob@host.com" 4890 ;PARTSTAT=ACCEPTED;CN=Jane Doe:MAILTO:jdoe@host1.com 4892 The following is an example of this property with a URI to the 4893 directory information associated with the attendee: 4895 ATTENDEE;CN=John Smith;DIR="ldap://host.com:6666/o=eDABC% 4896 20Industries,c=3DUS??(cn=3DBJim%20Dolittle)":MAILTO:jimdo@ 4897 host1.com 4899 The following is an example of this property with "delegatee" and 4900 "delegator" information for an event: 4902 ORGANIZER;CN=John Smith:MAILTO:jsmith@host.com 4903 ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=TENTATIVE;DELEGATED-FROM= 4904 "MAILTO:iamboss@host2.com";CN=Henry Cabot:MAILTO:hcabot@ 4905 host2.com 4906 ATTENDEE;ROLE=NON-PARTICIPANT;PARTSTAT=DELEGATED;DELEGATED-TO= 4907 "MAILTO:hcabot@host2.com";CN=The Big Cheese:MAILTO:iamboss 4908 @host2.com 4909 ATTENDEE;ROLE=REQ-PARTICIPANT;PARTSTAT=ACCEPTED;CN=Jane Doe 4910 :MAILTO:jdoe@host1.com 4912 Example: The following is an example of this property's use when 4913 another calendar user is acting on behalf of the "Attendee": 4915 ATTENDEE;SENT-BY=MAILTO:jan_doe@host1.com;CN=John Smith:MAILTO: 4916 jsmith@host1.com 4918 4.8.4.2 Contact 4920 Property Name: CONTACT 4922 Purpose: The property is used to represent contact information or 4923 alternately a reference to contact information associated with the 4924 calendar component. 4926 Value Type: TEXT 4928 Property Parameters: Non-standard, alternate text representation and 4929 language property parameters can be specified on this property. 4931 Conformance: The property can be specified in a "VEVENT", "VTODO", 4932 "VJOURNAL" or "VFREEBUSY" calendar component. 4934 Description: The property value consists of textual contact 4935 information. An alternative representation for the property value can 4936 also be specified that refers to a URI pointing to an alternate form, 4937 such as a vCard, for the contact information. 4939 Format Definition: The property is defined by the following notation: 4941 contact = "CONTACT" contparam ":" text CRLF 4943 contparam = *( 4945 ; the following are optional, 4946 ; but MUST NOT occur more than once 4948 (";" altrepparam) / (";" languageparam) / 4950 ; the following is optional, 4951 ; and MAY occur more than once 4953 (";" xparam) 4955 ) 4957 Example: The following is an example of this property referencing 4958 textual contact information: 4960 CONTACT:Jim Dolittle\, ABC Industries\, +1-919-555-1234 4961 The following is an example of this property with an alternate 4962 representation of a LDAP URI to a directory entry containing the 4963 contact information: 4965 CONTACT;ALTREP="ldap://host.com:6666/o=3DABC%20Industries\, 4966 c=3DUS??(cn=3DBJim%20Dolittle)":Jim Dolittle\, ABC Industries\, 4967 +1-919-555-1234 4969 The following is an example of this property with an alternate 4970 representation of a MIME body part containing the contact 4971 information, such as a vCard embedded in a [MIME-DIR] content-type: 4973 CONTACT;ALTREP="CID=":Jim 4974 Dolittle\, ABC Industries\, +1-919-555-1234 4976 The following is an example of this property referencing a network 4977 resource, such as a vCard object containing the contact information: 4979 CONTACT;ALTREP="http://host.com/pdi/jdoe.vcf":Jim 4980 Dolittle\, ABC Industries\, +1-919-555-1234 4982 4.8.4.3 Organizer 4984 Property Name: ORGANIZER 4986 Purpose: The property defines the organizer for a calendar component. 4988 Value Type: CAL-ADDRESS 4990 Property Parameters: Non-standard, language, common name, directory 4991 entry reference, sent by property parameters can be specified on this 4992 property. 4994 Conformance: This property MUST be specified in an iCalendar object 4995 that specifies a group scheduled calendar entity. This property MUST 4996 be specified in an iCalendar object that specifies the publication of 4997 a calendar user's busy time. This property MUST NOT be specified in 4998 an iCalendar object that specifies only a time zone definition or 4999 that defines calendar entities that are not group scheduled entities, 5000 but are entities only on a single user's calendar. 5002 Description: The property is specified within the "VEVENT", "VTODO", 5003 "VJOURNAL calendar components to specify the organizer of a group 5004 scheduled calendar entity. The property is specified within the 5005 "VFREEBUSY" calendar component to specify the calendar user 5006 requesting the free or busy time. When publishing a "VFREEBUSY" 5007 calendar component, the property is used to specify the calendar that 5008 the published busy time came from. 5010 The property has the property parameters CN, for specifying the 5011 common or display name associated with the "Organizer", DIR, for 5012 specifying a pointer to the directory information associated with the 5013 "Organizer", SENT-BY, for specifying another calendar user that is 5014 acting on behalf of the "Organizer". The non-standard parameters may 5015 also be specified on this property. If the LANGUAGE property 5016 parameter is specified, the identified language applies to the CN 5017 parameter value. 5019 Format Definition: The property is defined by the following notation: 5021 organizer = "ORGANIZER" orgparam ":" 5022 cal-address CRLF 5024 orgparam = *( 5026 ; the following are optional, 5027 ; but MUST NOT occur more than once 5029 (";" cnparam) / (";" dirparam) / (";" sentbyparam) / 5030 (";" languageparam) / 5032 ; the following is optional, 5033 ; and MAY occur more than once 5035 (";" xparam) 5037 ) 5039 Example: The following is an example of this property: 5041 ORGANIZER;CN=John Smith:MAILTO:jsmith@host1.com 5043 The following is an example of this property with a pointer to the 5044 directory information associated with the organizer: 5046 ORGANIZER;CN=JohnSmith;DIR="ldap://host.com:6666/o=3DDC%20Associ 5047 ates,c=3DUS??(cn=3DJohn%20Smith)":MAILTO:jsmith@host1.com 5049 The following is an example of this property used by another calendar 5050 user who is acting on behalf of the organizer, with responses 5051 intended to be sent back to the organizer, not the other calendar 5052 user: 5054 ORGANIZER;SENT-BY="MAILTO:jane_doe@host.com": 5055 MAILTO:jsmith@host1.com 5057 4.8.4.4 Recurrence ID 5059 Property Name: RECURRENCE-ID 5061 Purpose: This property is used in conjunction with the "UID" and 5062 "SEQUENCE" property to identify a specific instance of a recurring 5063 "VEVENT", "VTODO" or "VJOURNAL" calendar component. The property 5064 value is the effective value of the "DTSTART" property of the 5065 recurrence instance. 5067 Value Type: The default value type for this property is DATE-TIME. 5068 The time format can be any of the valid forms defined for a DATE-TIME 5069 value type. See DATE-TIME value type definition for specific 5070 interpretations of the various forms. The value type can be set to 5071 DATE. 5073 Property Parameters: Non-standard property, value data type, time 5074 zone identifier and recurrence identifier range parameters can be 5075 specified on this property. 5077 Conformance: This property can be specified in an iCalendar object 5078 containing a recurring calendar component. 5080 Description: The full range of calendar components specified by a 5081 recurrence set is referenced by referring to just the "UID" property 5082 value corresponding to the calendar component. The "RECURRENCE-ID" 5083 property allows the reference to an individual instance within the 5084 recurrence set. 5086 If the value of the "DTSTART" property is a DATE type value, then the 5087 value MUST be the calendar date for the recurrence instance. 5089 The date/time value is set to the time when the original recurrence 5090 instance would occur; meaning that if the intent is to change a 5091 Friday meeting to Thursday, the date/time is still set to the 5092 original Friday meeting. 5094 The "RECURRENCE-ID" property is used in conjunction with the "UID" 5095 and "SEQUENCE" property to identify a particular instance of a 5096 recurring event, to-do or journal. For a given pair of "UID" and 5097 "SEQUENCE" property values, the "RECURRENCE-ID" value for a 5098 recurrence instance is fixed. When the definition of the recurrence 5099 set for a calendar component changes, and hence the "SEQUENCE" 5100 property value changes, the "RECURRENCE-ID" for a given recurrence 5101 instance might also change.The "RANGE" parameter is used to specify 5102 the effective range of recurrence instances from the instance 5103 specified by the "RECURRENCE-ID" property value. The default value 5104 for the range parameter is the single recurrence instance only. The 5105 value can also be "THISANDPRIOR" to indicate a range defined by the 5106 given recurrence instance and all prior instances or the value can be 5107 "THISANDFUTURE" to indicate a range defined by the given recurrence 5108 instance and all subsequent instances. 5110 Format Definition: The property is defined by the following notation: 5112 recurid = "RECURRENCE-ID" ridparam ":" ridval CRLF 5114 ridparam = *( 5116 ; the following are optional, 5117 ; but MUST NOT occur more than once 5119 (";" "VALUE" "=" ("DATE-TIME" / "DATE)) / 5120 (";" tzidparam) / (";" rangeparam) / 5121 ; the following is optional, 5122 ; and MAY occur more than once 5124 (";" xparam) 5126 ) 5128 ridval = date-time / date 5129 ;Value MUST match value type 5131 Example: The following are examples of this property: 5133 RECURRENCE-ID;VALUE=DATE:19960401 5135 RECURRENCE-ID;RANGE=THISANDFUTURE:19960120T120000Z 5137 4.8.4.5 Related To 5139 Property Name: RELATED-TO 5141 Purpose: The property is used to represent a relationship or 5142 reference between one calendar component and another. 5144 Value Type: TEXT 5146 Property Parameters: Non-standard and relationship type property 5147 parameters can be specified on this property. 5149 Conformance: The property can be specified once in the "VEVENT", 5150 "VTODO" or "VJOURNAL" calendar components. 5152 Description: The property value consists of the persistent, globally 5153 unique identifier of another calendar component. This value would be 5154 represented in a calendar component by the "UID" property. 5156 By default, the property value points to another calendar component 5157 that has a PARENT relationship to the referencing object. The 5158 "RELTYPE" property parameter is used to either explicitly state the 5159 default PARENT relationship type to the referenced calendar component 5160 or to override the default PARENT relationship type and specify 5161 either a CHILD or SIBLING relationship. The PARENT relationship 5162 indicates that the calendar component is a subordinate of the 5163 referenced calendar component. The CHILD relationship indicates that 5164 the calendar component is a superior of the referenced calendar 5165 component. The SIBLING relationship indicates that the calendar 5166 component is a peer of the referenced calendar component. 5168 Changes to a calendar component referenced by this property can have 5169 an implicit impact on the related calendar component. For example, if 5170 a group event changes its start or end date or time, then the 5171 related, dependent events will need to have their start and end dates 5172 changed in a corresponding way. Similarly, if a PARENT calendar 5173 component is canceled or deleted, then there is an implied impact to 5174 the related CHILD calendar components. This property is intended only 5175 to provide information on the relationship of calendar components. It 5176 is up to the target calendar system to maintain any property 5177 implications of this relationship. 5179 Format Definition: The property is defined by the following notation: 5181 related = "RELATED-TO" [relparam] ":" text CRLF 5183 relparam = *( 5185 ; the following is optional, 5186 ; but MUST NOT occur more than once 5188 (";" reltypeparam) / 5190 ; the following is optional, 5191 ; and MAY occur more than once 5193 (";" xparm) 5195 ) 5197 The following is an example of this property: 5199 RELATED-TO: 5201 RELATED-TO:<19960401-080045-4000F192713-0052@host1.com> 5203 4.8.4.6 Uniform Resource Locator 5205 Property Name: URL 5207 Purpose: This property defines a Uniform Resource Locator (URL) 5208 associated with the iCalendar object. 5210 Value Type: URI 5212 Property Parameters: Non-standard property parameters can be 5213 specified on this property. 5215 Conformance: This property can be specified once in the "VEVENT", 5216 "VTODO", "VJOURNAL" or "VFREEBUSY" calendar components. 5218 Description: This property may be used in a calendar component to 5219 convey a location where a more dynamic rendition of the calendar 5220 information associated with the calendar component can be found. This 5221 memo does not attempt to standardize the form of the URI, nor the 5222 format of the resource pointed to by the property value. If the URL 5223 property and Content-Location MIME header are both specified, they 5224 MUST point to the same resource. 5226 Format Definition: The property is defined by the following notation: 5228 url = "URL" urlparam ":" uri CRLF 5229 urlparam = *(";" xparam) 5231 Example: The following is an example of this property: 5233 URL:http://abc.com/pub/calendars/jsmith/mytime.ics 5235 4.8.4.7 Unique Identifier 5237 Property Name: UID 5239 Purpose: This property defines the persistent, globally unique 5240 identifier for the calendar component. 5242 Value Type: TEXT 5244 Property Parameters: Non-standard property parameters can be 5245 specified on this property. 5247 Conformance: The property MUST be specified in the "VEVENT", "VTODO", 5248 "VJOURNAL" or "VFREEBUSY" calendar components. 5250 Description: The UID itself MUST be a globally unique identifier. The 5251 generator of the identifier MUST guarantee that the identifier is 5252 unique. There are several algorithms that can be used to accomplish 5253 this. The identifier is RECOMMENDED to be the identical syntax to the 5254 [RFC 822] addr-spec. A good method to assure uniqueness is to put the 5255 domain name or a domain literal IP address of the host on which the 5256 identifier was created on the right hand side of the "@", and on the 5257 left hand side, put a combination of the current calendar date and 5258 time of day (i.e., formatted in as a DATE-TIME value) along with some 5259 other currently unique (perhaps sequential) identifier available on 5260 the system (for example, a process id number). Using a date/time 5261 value on the left hand side and a domain name or domain literal on 5262 the right hand side makes it possible to guarantee uniqueness since 5263 no two hosts should be using the same domain name or IP address at 5264 the same time. Though other algorithms will work, it is RECOMMENDED 5265 that the right hand side contain some domain identifier (either of 5266 the host itself or otherwise) such that the generator of the message 5267 identifier can guarantee the uniqueness of the left hand side within 5268 the scope of that domain. 5270 This is the method for correlating scheduling messages with the 5271 referenced "VEVENT", "VTODO", or "VJOURNAL" calendar component. 5273 The full range of calendar components specified by a recurrence set 5274 is referenced by referring to just the "UID" property value 5275 corresponding to the calendar component. The "RECURRENCE-ID" property 5276 allows the reference to an individual instance within the recurrence 5277 set. 5279 This property is an important method for group scheduling 5280 applications to match requests with later replies, modifications or 5281 deletion requests. Calendaring and scheduling applications MUST 5282 generate this property in "VEVENT", "VTODO" and "VJOURNAL" calendar 5283 components to assure interoperability with other group scheduling 5284 applications. This identifier is created by the calendar system that 5285 generates an iCalendar object. 5287 Implementations MUST be able to receive and persist values of at 5288 least 255 characters for this property. 5290 Format Definition: The property is defined by the following notation: 5292 uid = "UID" uidparam ":" text CRLF 5294 uidparam = *(";" xparam) 5296 Example: The following is an example of this property: 5298 UID:19960401T080045Z-4000F192713-0052@host1.com 5300 4.8.5 Recurrence Component Properties 5302 The following properties specify recurrence information in calendar 5303 components. 5305 4.8.5.1 Exception Date/Times 5307 Property Name: EXDATE 5309 Purpose: This property defines the list of date/time exceptions for a 5310 recurring calendar component. 5312 Value Type: The default value type for this property is DATE-TIME. 5313 The value type can be set to DATE. 5315 Property Parameters: Non-standard, value data type and time zone 5316 identifier property parameters can be specified on this property. 5318 Conformance: This property can be specified in an iCalendar object 5319 that includes a recurring calendar component. 5321 Description: The exception dates, if specified, are used in computing 5322 the recurrence set. The recurrence set is the complete set of 5323 recurrence instances for a calendar component. The recurrence set is 5324 generated by considering the initial "DTSTART" property along with 5325 the "RRULE", "RDATE", "EXDATE" and "EXRULE" properties contained 5326 within the iCalendar object. The "DTSTART" property defines the first 5327 instance in the recurrence set. Multiple instances of the "RRULE" and 5328 "EXRULE" properties can also be specified to define more 5329 sophisticated recurrence sets. The final recurrence set is generated 5330 by gathering all of the start date-times generated by any of the 5331 specified "RRULE" and "RDATE" properties, and then excluding any 5332 start date and times which fall within the union of start date and 5333 times generated by any specified "EXRULE" and "EXDATE" properties. 5334 This implies that start date and times within exclusion related 5335 properties (i.e., "EXDATE" and "EXRULE") take precedence over those 5336 specified by inclusion properties (i.e., "RDATE" and "RRULE"). Where 5337 duplicate instances are generated by the "RRULE" and "RDATE" 5338 properties, only one recurrence is considered. Duplicate instances 5339 are ignored. 5341 The "EXDATE" property can be used to exclude the value specified in 5342 "DTSTART". However, in such cases the original "DTSTART" date MUST 5343 still be maintained by the calendaring and scheduling system because 5344 the original "DTSTART" value has inherent usage dependencies by other 5345 properties such as the "RECURRENCE-ID". 5347 Format Definition: The property is defined by the following notation: 5349 exdate = "EXDATE" exdtparam ":" exdtval *("," exdtval) CRLF 5351 exdtparam = *( 5353 ; the following are optional, 5354 ; but MUST NOT occur more than once 5356 (";" "VALUE" "=" ("DATE-TIME" / "DATE")) / 5357 (";" tzidparam) / 5359 ; the following is optional, 5360 ; and MAY occur more than once 5362 (";" xparam) 5364 ) 5366 exdtval = date-time / date 5367 ;Value MUST match value type 5369 Example: The following is an example of this property: 5371 EXDATE:19960402T010000Z,19960403T010000Z,19960404T010000Z 5373 4.8.5.2 Exception Rule 5375 Property Name: EXRULE 5377 Purpose: This property defines a rule or repeating pattern for an 5378 exception to a recurrence set. 5380 Value Type: RECUR 5382 Property Parameters: Non-standard property parameters can be 5383 specified on this property. 5385 Conformance: This property can be specified in "VEVENT", "VTODO" or 5386 "VJOURNAL" calendar components. 5388 Description: The exception rule, if specified, is used in computing 5389 the recurrence set. The recurrence set is the complete set of 5390 recurrence instances for a calendar component. The recurrence set is 5391 generated by considering the initial "DTSTART" property along with 5392 the "RRULE", "RDATE", "EXDATE" and "EXRULE" properties contained 5393 within the iCalendar object. The "DTSTART" defines the first instance 5394 in the recurrence set. Multiple instances of the "RRULE" and "EXRULE" 5395 properties can also be specified to define more sophisticated 5396 recurrence sets. The final recurrence set is generated by gathering 5397 all of the start date-times generated by any of the specified "RRULE" 5398 and "RDATE" properties, and excluding any start date and times which 5399 fall within the union of start date and times generated by any 5400 specified "EXRULE" and "EXDATE" properties. This implies that start 5401 date and times within exclusion related properties (i.e., "EXDATE" 5402 and "EXRULE") take precedence over those specified by inclusion 5403 properties (i.e., "RDATE" and "RRULE"). Where duplicate instances are 5404 generated by the "RRULE" and "RDATE" properties, only one recurrence 5405 is considered. Duplicate instances are ignored. 5407 The "EXRULE" property can be used to exclude the value specified in 5408 "DTSTART". However, in such cases the original "DTSTART" date MUST 5409 still be maintained by the calendaring and scheduling system because 5410 the original "DTSTART" value has inherent usage dependencies by other 5411 properties such as the "RECURRENCE-ID". 5413 Format Definition: The property is defined by the following notation: 5415 exrule = "EXRULE" exrparam ":" recur CRLF 5417 exrparam = *(";" xparam) 5419 Example: The following are examples of this property. Except every 5420 other week, on Tuesday and Thursday for 4 occurrences: 5422 EXRULE:FREQ=WEEKLY;COUNT=4;INTERVAL=2;BYDAY=TU,TH 5424 Except daily for 10 occurrences: 5426 EXRULE:FREQ=DAILY;COUNT=10 5428 Except yearly in June and July for 8 occurrences: 5430 EXRULE:FREQ=YEARLY;COUNT=8;BYMONTH=6,7 5432 4.8.5.3 Recurrence Date/Times 5434 Property Name: RDATE 5436 Purpose: This property defines the list of date/times for a 5437 recurrence set. 5439 Value Type: The default value type for this property is DATE-TIME. 5440 The value type can be set to DATE or PERIOD. 5442 Property Parameters: Non-standard, value data type and time zone 5443 identifier property parameters can be specified on this property. 5445 Conformance: The property can be specified in "VEVENT", "VTODO", 5446 "VJOURNAL" or "VTIMEZONE" calendar components. 5448 Description: This property can appear along with the "RRULE" property 5449 to define an aggregate set of repeating occurrences. When they both 5450 appear in an iCalendar object, the recurring events are defined by 5451 the union of occurrences defined by both the "RDATE" and "RRULE". 5453 The recurrence dates, if specified, are used in computing the 5454 recurrence set. The recurrence set is the complete set of recurrence 5455 instances for a calendar component. The recurrence set is generated 5456 by considering the initial "DTSTART" property along with the "RRULE", 5457 "RDATE", "EXDATE" and "EXRULE" properties contained within the 5458 iCalendar object. The "DTSTART" property defines the first instance 5459 in the recurrence set. Multiple instances of the "RRULE" and "EXRULE" 5460 properties can also be specified to define more sophisticated 5461 recurrence sets. The final recurrence set is generated by gathering 5462 all of the start date/times generated by any of the specified "RRULE" 5463 and "RDATE" properties, and excluding any start date/times which fall 5464 within the union of start date/times generated by any specified 5465 "EXRULE" and "EXDATE" properties. This implies that start date/times 5466 within exclusion related properties (i.e., "EXDATE" and "EXRULE") 5467 take precedence over those specified by inclusion properties (i.e., 5468 "RDATE" and "RRULE"). Where duplicate instances are generated by the 5469 "RRULE" and "RDATE" properties, only one recurrence is considered. 5470 Duplicate instances are ignored. 5472 Format Definition: The property is defined by the following notation: 5474 rdate = "RDATE" rdtparam ":" rdtval *("," rdtval) CRLF 5476 rdtparam = *( 5478 ; the following are optional, 5479 ; but MUST NOT occur more than once 5481 (";" "VALUE" "=" ("DATE-TIME" / "DATE" / "PERIOD")) / 5482 (";" tzidparam) / 5484 ; the following is optional, 5485 ; and MAY occur more than once 5487 (";" xparam) 5489 ) 5491 rdtval = date-time / date / period 5492 ;Value MUST match value type 5494 Example: The following are examples of this property: 5496 RDATE:19970714T123000Z 5498 RDATE;TZID=US-EASTERN:19970714T083000 5499 RDATE;VALUE=PERIOD:19960403T020000Z/19960403T040000Z, 5500 19960404T010000Z/PT3H 5502 RDATE;VALUE=DATE:19970101,19970120,19970217,19970421 5503 19970526,19970704,19970901,19971014,19971128,19971129,19971225 5505 4.8.5.4 Recurrence Rule 5507 Property Name: RRULE 5509 Purpose: This property defines a rule or repeating pattern for 5510 recurring events, to-dos, or time zone definitions. 5512 Value Type: RECUR 5514 Property Parameters: Non-standard property parameters can be 5515 specified on this property. 5517 Conformance: This property can be specified one or more times in 5518 recurring "VEVENT", "VTODO" and "VJOURNAL" calendar components. It 5519 can also be specified once in each STANDARD or DAYLIGHT sub-component 5520 of the "VTIMEZONE" calendar component. 5522 Description: The recurrence rule, if specified, is used in computing 5523 the recurrence set. The recurrence set is the complete set of 5524 recurrence instances for a calendar component. The recurrence set is 5525 generated by considering the initial "DTSTART" property along with 5526 the "RRULE", "RDATE", "EXDATE" and "EXRULE" properties contained 5527 within the iCalendar object. The "DTSTART" property defines the first 5528 instance in the recurrence set. Multiple instances of the "RRULE" and 5529 "EXRULE" properties can also be specified to define more 5530 sophisticated recurrence sets. The final recurrence set is generated 5531 by gathering all of the start date/times generated by any of the 5532 specified "RRULE" and "RDATE" properties, and excluding any start 5533 date/times which fall within the union of start date/times generated 5534 by any specified "EXRULE" and "EXDATE" properties. This implies that 5535 start date/times within exclusion related properties (i.e., "EXDATE" 5536 and "EXRULE") take precedence over those specified by inclusion 5537 properties (i.e., "RDATE" and "RRULE"). Where duplicate instances are 5538 generated by the "RRULE" and "RDATE" properties, only one recurrence 5539 is considered. Duplicate instances are ignored. 5541 The "DTSTART" and "DTEND" property pair or "DTSTART" and "DURATION" 5542 property pair, specified within the iCalendar object defines the 5543 first instance of the recurrence. When used with a recurrence rule, 5544 the "DTSTART" and "DTEND" properties MUST be specified in local time 5545 and the appropriate set of "VTIMEZONE" calendar components MUST be 5546 included. For detail on the usage of the "VTIMEZONE" calendar 5547 component, see the "VTIMEZONE" calendar component definition. 5549 Any duration associated with the iCalendar object applies to all 5550 members of the generated recurrence set. Any modified duration for 5551 specific recurrences MUST be explicitly specified using the "RDATE" 5552 property. 5554 Format Definition: This property is defined by the following 5555 notation: 5557 rrule = "RRULE" rrulparam ":" recur CRLF 5559 rrulparam = *(";" xparam) 5561 Example: All examples assume the Eastern United States time zone. 5563 Daily for 10 occurrences: 5565 DTSTART;TZID=US-Eastern:19970902T090000 5566 RRULE:FREQ=DAILY;COUNT=10 5568 ==> (1997 9:00 AM EDT)September 2-11 5570 Daily until December 24, 1997: 5572 DTSTART;TZID=US-Eastern:19970902T090000 5573 RRULE:FREQ=DAILY;UNTIL=19971224T000000Z 5575 ==> (1997 9:00 AM EDT)September 2-30;October 1-25 5576 (1997 9:00 AM EST)October 26-31;November 1-30;December 1-23 5578 Every other day - forever: 5580 DTSTART;TZID=US-Eastern:19970902T090000 5581 RRULE:FREQ=DAILY;INTERVAL=2 5582 ==> (1997 9:00 AM EDT)September2,4,6,8...24,26,28,30; 5583 October 2,4,6...20,22,24 5584 (1997 9:00 AM EST)October 26,28,30;November 1,3,5,7...25,27,29; 5585 Dec 1,3,... 5587 Every 10 days, 5 occurrences: 5589 DTSTART;TZID=US-Eastern:19970902T090000 5590 RRULE:FREQ=DAILY;INTERVAL=10;COUNT=5 5592 ==> (1997 9:00 AM EDT)September 2,12,22;October 2,12 5594 Everyday in January, for 3 years: 5596 DTSTART;TZID=US-Eastern:19980101T090000 5597 RRULE:FREQ=YEARLY;UNTIL=20000131T090000Z; 5598 BYMONTH=1;BYDAY=SU,MO,TU,WE,TH,FR,SA 5599 or 5600 RRULE:FREQ=DAILY;UNTIL=20000131T090000Z;BYMONTH=1 5602 ==> (1998 9:00 AM EDT)January 1-31 5603 (1999 9:00 AM EDT)January 1-31 5604 (2000 9:00 AM EDT)January 1-31 5606 Weekly for 10 occurrences 5607 DTSTART;TZID=US-Eastern:19970902T090000 5608 RRULE:FREQ=WEEKLY;COUNT=10 5610 ==> (1997 9:00 AM EDT)September 2,9,16,23,30;October 7,14,21 5611 (1997 9:00 AM EST)October 28;November 4 5613 Weekly until December 24, 1997 5615 DTSTART;TZID=US-Eastern:19970902T090000 5616 RRULE:FREQ=WEEKLY;UNTIL=19971224T000000Z 5618 ==> (1997 9:00 AM EDT)September 2,9,16,23,30;October 7,14,21 5619 (1997 9:00 AM EST)October 28;November 4,11,18,25; 5620 December 2,9,16,23 5622 Every other week - forever: 5624 DTSTART;TZID=US-Eastern:19970902T090000 5625 RRULE:FREQ=WEEKLY;INTERVAL=2;WKST=SU 5627 ==> (1997 9:00 AM EDT)September 2,16,30;October 14 5628 (1997 9:00 AM EST)October 28;November 11,25;December 9,23 5629 (1998 9:00 AM EST)January 6,20;February 5630 ... 5632 Weekly on Tuesday and Thursday for 5 weeks: 5634 DTSTART;TZID=US-Eastern:19970902T090000 5635 RRULE:FREQ=WEEKLY;UNTIL=19971007T000000Z;WKST=SU;BYDAY=TU,TH 5636 or 5637 RRULE:FREQ=WEEKLY;COUNT=10;WKST=SU;BYDAY=TU,TH 5639 ==> (1997 9:00 AM EDT)September 2,4,9,11,16,18,23,25,30;October 2 5641 Every other week on Monday, Wednesday and Friday until December 24, 5642 1997, but starting on Tuesday, September 2, 1997: 5644 DTSTART;TZID=US-Eastern:19970902T090000 5645 RRULE:FREQ=WEEKLY;INTERVAL=2;UNTIL=19971224T000000Z;WKST=SU; 5646 BYDAY=MO,WE,FR 5647 ==> (1997 9:00 AM EDT)September 2,3,5,15,17,19,29;October 5648 1,3,13,15,17 5649 (1997 9:00 AM EST)October 27,29,31;November 10,12,14,24,26,28; 5650 December 8,10,12,22 5652 Every other week on Tuesday and Thursday, for 8 occurrences: 5654 DTSTART;TZID=US-Eastern:19970902T090000 5655 RRULE:FREQ=WEEKLY;INTERVAL=2;COUNT=8;WKST=SU;BYDAY=TU,TH 5657 ==> (1997 9:00 AM EDT)September 2,4,16,18,30;October 2,14,16 5659 Monthly on the 1st Friday for ten occurrences: 5661 DTSTART;TZID=US-Eastern:19970905T090000 5662 RRULE:FREQ=MONTHLY;COUNT=10;BYDAY=1FR 5664 ==> (1997 9:00 AM EDT)September 5;October 3 5665 (1997 9:00 AM EST)November 7;Dec 5 5666 (1998 9:00 AM EST)January 2;February 6;March 6;April 3 5667 (1998 9:00 AM EDT)May 1;June 5 5669 Monthly on the 1st Friday until December 24, 1997: 5671 DTSTART;TZID=US-Eastern:19970905T090000 5672 RRULE:FREQ=MONTHLY;UNTIL=19971224T000000Z;BYDAY=1FR 5674 ==> (1997 9:00 AM EDT)September 5;October 3 5675 (1997 9:00 AM EST)November 7;December 5 5677 Every other month on the 1st and last Sunday of the month for 10 5678 occurrences: 5680 DTSTART;TZID=US-Eastern:19970907T090000 5681 RRULE:FREQ=MONTHLY;INTERVAL=2;COUNT=10;BYDAY=1SU,-1SU 5683 ==> (1997 9:00 AM EDT)September 7,28 5684 (1997 9:00 AM EST)November 2,30 5685 (1998 9:00 AM EST)January 4,25;March 1,29 5686 (1998 9:00 AM EDT)May 3,31 5688 Monthly on the second to last Monday of the month for 6 months: 5690 DTSTART;TZID=US-Eastern:19970922T090000 5691 RRULE:FREQ=MONTHLY;COUNT=6;BYDAY=-2MO 5693 ==> (1997 9:00 AM EDT)September 22;October 20 5694 (1997 9:00 AM EST)November 17;December 22 5695 (1998 9:00 AM EST)January 19;February 16 5697 Monthly on the third to the last day of the month, forever: 5699 DTSTART;TZID=US-Eastern:19970928T090000 5700 RRULE:FREQ=MONTHLY;BYMONTHDAY=-3 5702 ==> (1997 9:00 AM EDT)September 28 5703 (1997 9:00 AM EST)October 29;November 28;December 29 5704 (1998 9:00 AM EST)January 29;February 26 5705 ... 5707 Monthly on the 2nd and 15th of the month for 10 occurrences: 5709 DTSTART;TZID=US-Eastern:19970902T090000 5710 RRULE:FREQ=MONTHLY;COUNT=10;BYMONTHDAY=2,15 5712 ==> (1997 9:00 AM EDT)September 2,15;October 2,15 5713 (1997 9:00 AM EST)November 2,15;December 2,15 5714 (1998 9:00 AM EST)January 2,15 5715 Monthly on the first and last day of the month for 10 occurrences: 5717 DTSTART;TZID=US-Eastern:19970930T090000 5718 RRULE:FREQ=MONTHLY;COUNT=10;BYMONTHDAY=1,-1 5720 ==> (1997 9:00 AM EDT)September 30;October 1 5721 (1997 9:00 AM EST)October 31;November 1,30;December 1,31 5722 (1998 9:00 AM EST)January 1,31;February 1 5724 Every 18 months on the 10th thru 15th of the month for 10 5725 occurrences: 5727 DTSTART;TZID=US-Eastern:19970910T090000 5728 RRULE:FREQ=MONTHLY;INTERVAL=18;COUNT=10;BYMONTHDAY=10,11,12,13,14, 5729 15 5731 ==> (1997 9:00 AM EDT)September 10,11,12,13,14,15 5732 (1999 9:00 AM EST)March 10,11,12,13 5734 Every Tuesday, every other month: 5736 DTSTART;TZID=US-Eastern:19970902T090000 5737 RRULE:FREQ=MONTHLY;INTERVAL=2;BYDAY=TU 5739 ==> (1997 9:00 AM EDT)September 2,9,16,23,30 5740 (1997 9:00 AM EST)November 4,11,18,25 5741 (1998 9:00 AM EST)January 6,13,20,27;March 3,10,17,24,31 5742 ... 5744 Yearly in June and July for 10 occurrences: 5746 DTSTART;TZID=US-Eastern:19970610T090000 5747 RRULE:FREQ=YEARLY;COUNT=10;BYMONTH=6,7 5749 ==> (1997 9:00 AM EDT)June 10;July 10 5750 (1998 9:00 AM EDT)June 10;July 10 5751 (1999 9:00 AM EDT)June 10;July 10 5752 (2000 9:00 AM EDT)June 10;July 10 5753 (2001 9:00 AM EDT)June 10;July 10 5754 Note: Since none of the BYDAY, BYMONTHDAY or BYYEARDAY components 5755 are specified, the day is gotten from DTSTART 5757 Every other year on January, February, and March for 10 occurrences: 5759 DTSTART;TZID=US-Eastern:19970310T090000 5760 RRULE:FREQ=YEARLY;INTERVAL=2;COUNT=10;BYMONTH=1,2,3 5762 ==> (1997 9:00 AM EST)March 10 5763 (1999 9:00 AM EST)January 10;February 10;March 10 5764 (2001 9:00 AM EST)January 10;February 10;March 10 5765 (2003 9:00 AM EST)January 10;February 10;March 10 5767 Every 3rd year on the 1st, 100th and 200th day for 10 occurrences: 5769 DTSTART;TZID=US-Eastern:19970101T090000 5770 RRULE:FREQ=YEARLY;INTERVAL=3;COUNT=10;BYYEARDAY=1,100,200 5772 ==> (1997 9:00 AM EST)January 1 5773 (1997 9:00 AM EDT)April 10;July 19 5774 (2000 9:00 AM EST)January 1 5775 (2000 9:00 AM EDT)April 9;July 18 5776 (2003 9:00 AM EST)January 1 5777 (2003 9:00 AM EDT)April 10;July 19 5778 (2006 9:00 AM EST)January 1 5780 Every 20th Monday of the year, forever: 5782 DTSTART;TZID=US-Eastern:19970519T090000 5783 RRULE:FREQ=YEARLY;BYDAY=20MO 5785 ==> (1997 9:00 AM EDT)May 19 5786 (1998 9:00 AM EDT)May 18 5787 (1999 9:00 AM EDT)May 17 5788 ... 5790 Monday of week number 20 (where the default start of the week is 5791 Monday), forever: 5793 DTSTART;TZID=US-Eastern:19970512T090000 5794 RRULE:FREQ=YEARLY;BYWEEKNO=20;BYDAY=MO 5796 ==> (1997 9:00 AM EDT)May 12 5797 (1998 9:00 AM EDT)May 11 5798 (1999 9:00 AM EDT)May 17 5799 ... 5801 Every Thursday in March, forever: 5803 DTSTART;TZID=US-Eastern:19970313T090000 5804 RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=TH 5806 ==> (1997 9:00 AM EST)March 13,20,27 5807 (1998 9:00 AM EST)March 5,12,19,26 5808 (1999 9:00 AM EST)March 4,11,18,25 5809 ... 5811 Every Thursday, but only during June, July, and August, forever: 5813 DTSTART;TZID=US-Eastern:19970605T090000 5814 RRULE:FREQ=YEARLY;BYDAY=TH;BYMONTH=6,7,8 5816 ==> (1997 9:00 AM EDT)June 5,12,19,26;July 3,10,17,24,31; 5817 August 7,14,21,28 5818 (1998 9:00 AM EDT)June 4,11,18,25;July 2,9,16,23,30; 5819 August 6,13,20,27 5820 (1999 9:00 AM EDT)June 3,10,17,24;July 1,8,15,22,29; 5821 August 5,12,19,26 5822 ... 5824 Every Friday the 13th, forever: 5826 DTSTART;TZID=US-Eastern:19970902T090000 5827 EXDATE;TZID=US-Eastern:19970902T090000 5828 RRULE:FREQ=MONTHLY;BYDAY=FR;BYMONTHDAY=13 5830 ==> (1998 9:00 AM EST)February 13;March 13;November 13 5831 (1999 9:00 AM EDT)August 13 5832 (2000 9:00 AM EDT)October 13 5833 ... 5835 The first Saturday that follows the first Sunday of the month, 5836 forever: 5838 DTSTART;TZID=US-Eastern:19970913T090000 5839 RRULE:FREQ=MONTHLY;BYDAY=SA;BYMONTHDAY=7,8,9,10,11,12,13 5841 ==> (1997 9:00 AM EDT)September 13;October 11 5842 (1997 9:00 AM EST)November 8;December 13 5843 (1998 9:00 AM EST)January 10;February 7;March 7 5844 (1998 9:00 AM EDT)April 11;May 9;June 13... 5845 ... 5847 Every four years, the first Tuesday after a Monday in November, 5848 forever (U.S. Presidential Election day): 5850 DTSTART;TZID=US-Eastern:19961105T090000 5851 RRULE:FREQ=YEARLY;INTERVAL=4;BYMONTH=11;BYDAY=TU;BYMONTHDAY=2,3,4, 5852 5,6,7,8 5854 ==> (1996 9:00 AM EST)November 5 5855 (2000 9:00 AM EST)November 7 5856 (2004 9:00 AM EST)November 2 5857 ... 5859 The 3rd instance into the month of one of Tuesday, Wednesday or 5860 Thursday, for the next 3 months: 5862 DTSTART;TZID=US-Eastern:19970904T090000 5863 RRULE:FREQ=MONTHLY;COUNT=3;BYDAY=TU,WE,TH;BYSETPOS=3 5865 ==> (1997 9:00 AM EDT)September 4;October 7 5866 (1997 9:00 AM EST)November 6 5868 The 2nd to last weekday of the month: 5870 DTSTART;TZID=US-Eastern:19970929T090000 5871 RRULE:FREQ=MONTHLY;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-2 5873 ==> (1997 9:00 AM EDT)September 29 5874 (1997 9:00 AM EST)October 30;November 27;December 30 5875 (1998 9:00 AM EST)January 29;February 26;March 30 5876 ... 5878 Every 3 hours from 9:00 AM to 5:00 PM on a specific day: 5880 DTSTART;TZID=US-Eastern:19970902T090000 5881 RRULE:FREQ=HOURLY;INTERVAL=3;UNTIL=19970902T170000Z 5883 ==> (September 2, 1997 EDT)09:00,12:00,15:00 5885 Every 15 minutes for 6 occurrences: 5887 DTSTART;TZID=US-Eastern:19970902T090000 5888 RRULE:FREQ=MINUTELY;INTERVAL=15;COUNT=6 5890 ==> (September 2, 1997 EDT)09:00,09:15,09:30,09:45,10:00,10:15 5892 Every hour and a half for 4 occurrences: 5894 DTSTART;TZID=US-Eastern:19970902T090000 5895 RRULE:FREQ=MINUTELY;INTERVAL=90;COUNT=4 5897 ==> (September 2, 1997 EDT)09:00,10:30;12:00;13:30 5899 Every 20 minutes from 9:00 AM to 4:40 PM every day: 5901 DTSTART;TZID=US-Eastern:19970902T090000 5902 RRULE:FREQ=DAILY;BYHOUR=9,10,11,12,13,14,15,16;BYMINUTE=0,20,40 5903 or 5904 RRULE:FREQ=MINUTELY;INTERVAL=20;BYHOUR=9,10,11,12,13,14,15,16 5906 ==> (September 2, 1997 EDT)9:00,9:20,9:40,10:00,10:20, 5907 ... 16:00,16:20,16:40 5908 (September 3, 1997 EDT)9:00,9:20,9:40,10:00,10:20, 5909 ...16:00,16:20,16:40 5910 ... 5912 An example where the days generated makes a difference because of 5913 WKST: 5915 DTSTART;TZID=US-Eastern:19970805T090000 5916 RRULE:FREQ=WEEKLY;INTERVAL=2;COUNT=4;BYDAY=TU,SU;WKST=MO 5918 ==> (1997 EDT)Aug 5,10,19,24 5920 changing only WKST from MO to SU, yields different results... 5922 DTSTART;TZID=US-Eastern:19970805T090000 5923 RRULE:FREQ=WEEKLY;INTERVAL=2;COUNT=4;BYDAY=TU,SU;WKST=SU 5924 ==> (1997 EDT)August 5,17,19,31 5926 4.8.6 Alarm Component Properties 5928 The following properties specify alarm information in calendar 5929 components. 5931 4.8.6.1 Action 5933 Property Name: ACTION 5935 Purpose: This property defines the action to be invoked when an alarm 5936 is triggered. 5938 Value Type: TEXT 5940 Property Parameters: Non-standard property parameters can be 5941 specified on this property. 5943 Conformance: This property MUST be specified once in a "VALARM" 5944 calendar component. 5946 Description: Each "VALARM" calendar component has a particular type 5947 of action associated with it. This property specifies the type of 5948 action 5950 Format Definition: The property is defined by the following notation: 5952 action = "ACTION" actionparam ":" actionvalue CRLF 5954 actionparam = *(";" xparam) 5956 actionvalue = "AUDIO" / "DISPLAY" / "EMAIL" / "PROCEDURE" 5957 / iana-token / x-name 5959 Example: The following are examples of this property in a "VALARM" 5960 calendar component: 5962 ACTION:AUDIO 5964 ACTION:DISPLAY 5966 ACTION:PROCEDURE 5968 4.8.6.2 Repeat Count 5970 Property Name: REPEAT 5972 Purpose: This property defines the number of time the alarm should be 5973 repeated, after the initial trigger. 5975 Value Type: INTEGER 5977 Property Parameters: Non-standard property parameters can be 5978 specified on this property. 5980 Conformance: This property can be specified in a "VALARM" calendar 5981 component. 5983 Description: If the alarm triggers more than once, then this property 5984 MUST be specified along with the "DURATION" property. 5986 Format Definition: The property is defined by the following notation: 5988 repeatcnt = "REPEAT" repparam ":" integer CRLF 5989 ;Default is "0", zero. 5991 repparam = *(";" xparam) 5993 Example: The following is an example of this property for an alarm 5994 that repeats 4 additional times with a 5 minute delay after the 5995 initial triggering of the alarm: 5997 REPEAT:4 5998 DURATION:PT5M 6000 4.8.6.3 Trigger 6002 Property Name: TRIGGER 6004 Purpose: This property specifies when an alarm will trigger. 6006 Value Type: The default value type is DURATION. The value type can be 6007 set to a DATE-TIME value type, in which case the value MUST specify a 6008 UTC formatted DATE-TIME value. 6010 Property Parameters: Non-standard, value data type, time zone 6011 identifier or trigger relationship property parameters can be 6012 specified on this property. The trigger relationship property 6013 parameter MUST only be specified when the value type is DURATION. 6015 Conformance: This property MUST be specified in the "VALARM" calendar 6016 component. 6018 Description: Within the "VALARM" calendar component, this property 6019 defines when the alarm will trigger. The default value type is 6020 DURATION, specifying a relative time for the trigger of the alarm. 6021 The default duration is relative to the start of an event or to-do 6022 that the alarm is associated with. The duration can be explicitly set 6023 to trigger from either the end or the start of the associated event 6024 or to-do with the "RELATED" parameter. A value of START will set the 6025 alarm to trigger off the start of the associated event or to-do. A 6026 value of END will set the alarm to trigger off the end of the 6027 associated event or to-do. 6029 Either a positive or negative duration may be specified for the 6030 "TRIGGER" property. An alarm with a positive duration is triggered 6031 after the associated start or end of the event or to-do. An alarm 6032 with a negative duration is triggered before the associated start or 6033 end of the event or to-do. 6035 The "RELATED" property parameter is not valid if the value type of 6036 the property is set to DATE-TIME (i.e., for an absolute date and time 6037 alarm trigger). If a value type of DATE-TIME is specified, then the 6038 property value MUST be specified in the UTC time format. If an 6039 absolute trigger is specified on an alarm for a recurring event or 6040 to-do, then the alarm will only trigger for the specified absolute 6041 date/time, along with any specified repeating instances. 6043 If the trigger is set relative to START, then the "DTSTART" property 6044 MUST be present in the associated "VEVENT" or "VTODO" calendar 6045 component. If an alarm is specified for an event with the trigger set 6046 relative to the END, then the "DTEND" property or the "DSTART" and 6047 "DURATION' properties MUST be present in the associated "VEVENT" 6048 calendar component. If the alarm is specified for a to-do with a 6049 trigger set relative to the END, then either the "DUE" property or 6050 the "DSTART" and "DURATION' properties MUST be present in the 6051 associated "VTODO" calendar component. 6053 Alarms specified in an event or to-do which is defined in terms of a 6054 DATE value type will be triggered relative to 00:00:00 UTC on the 6055 specified date. For example, if "DTSTART:19980205, then the duration 6056 trigger will be relative to19980205T000000Z. 6058 Format Definition: The property is defined by the following notation: 6060 trigger = "TRIGGER" (trigrel / trigabs) 6062 trigrel = *( 6064 ; the following are optional, 6065 ; but MUST NOT occur more than once 6067 (";" "VALUE" "=" "DURATION") / 6068 (";" trigrelparam) / 6070 ; the following is optional, 6071 ; and MAY occur more than once 6073 (";" xparam) 6075 ) ":" dur-value 6077 trigabs = 1*( 6079 ; the following is REQUIRED, 6080 ; but MUST NOT occur more than once 6082 (";" "VALUE" "=" "DATE-TIME") / 6084 ; the following is optional, 6085 ; and MAY occur more than once 6087 (";" xparam) 6089 ) ":" date-time 6091 Example: A trigger set 15 minutes prior to the start of the event or 6092 to-do. 6094 TRIGGER:-P15M 6096 A trigger set 5 minutes after the end of the event or to-do. 6098 TRIGGER;RELATED=END:P5M 6100 A trigger set to an absolute date/time. 6102 TRIGGER;VALUE=DATE-TIME:19980101T050000Z 6104 4.8.7 Change Management Component Properties 6106 The following properties specify change management information in 6107 calendar components. 6109 4.8.7.1 Date/Time Created 6111 Property Name: CREATED 6113 Purpose: This property specifies the date and time that the calendar 6114 information was created by the calendar user agent in the calendar 6115 store. 6117 Note: This is analogous to the creation date and time for a file 6118 in the file system. 6120 Value Type: DATE-TIME 6122 Property Parameters: Non-standard property parameters can be 6123 specified on this property. 6125 Conformance: The property can be specified once in "VEVENT", "VTODO" 6126 or "VJOURNAL" calendar components. 6128 Description: The date and time is a UTC value. 6130 Format Definition: The property is defined by the following notation: 6132 created = "CREATED" creaparam ":" date-time CRLF 6134 creaparam = *(";" xparam) 6136 Example: The following is an example of this property: 6138 CREATED:19960329T133000Z 6140 4.8.7.2 Date/Time Stamp 6142 Property Name: DTSTAMP 6144 Purpose: The property indicates the date/time that the instance of 6145 the iCalendar object was created. 6147 Value Type: DATE-TIME 6148 Property Parameters: Non-standard property parameters can be 6149 specified on this property. 6151 Conformance: This property MUST be included in the "VEVENT", "VTODO", 6152 "VJOURNAL" or "VFREEBUSY" calendar components. 6154 Description: The value MUST be specified in the UTC time format. 6156 This property is also useful to protocols such as [IMIP] that have 6157 inherent latency issues with the delivery of content. This property 6158 will assist in the proper sequencing of messages containing iCalendar 6159 objects. 6161 This property is different than the "CREATED" and "LAST-MODIFIED" 6162 properties. These two properties are used to specify when the 6163 particular calendar data in the calendar store was created and last 6164 modified. This is different than when the iCalendar object 6165 representation of the calendar service information was created or 6166 last modified. 6168 Format Definition: The property is defined by the following notation: 6170 dtstamp = "DTSTAMP" stmparam ":" date-time CRLF 6172 stmparam = *(";" xparam) 6174 Example: 6176 DTSTAMP:19971210T080000Z 6178 4.8.7.3 Last Modified 6180 Property Name: LAST-MODIFIED 6182 Purpose: The property specifies the date and time that the 6183 information associated with the calendar component was last revised 6184 in the calendar store. 6186 Note: This is analogous to the modification date and time for a 6187 file in the file system. 6189 Value Type: DATE-TIME 6191 Property Parameters: Non-standard property parameters can be 6192 specified on this property. 6194 Conformance: This property can be specified in the "EVENT", "VTODO", 6195 "VJOURNAL" or "VTIMEZONE" calendar components. 6197 Description: The property value MUST be specified in the UTC time 6198 format. 6200 Format Definition: The property is defined by the following notation: 6202 last-mod = "LAST-MODIFIED" lstparam ":" date-time CRLF 6204 lstparam = *(";" xparam) 6206 Example: The following is are examples of this property: 6208 LAST-MODIFIED:19960817T133000Z 6210 4.8.7.4 Sequence Number 6212 Property Name: SEQUENCE 6214 Purpose: This property defines the revision sequence number of the 6215 calendar component within a sequence of revisions. 6217 Value Type: integer 6219 Property Parameters: Non-standard property parameters can be 6220 specified on this property. 6222 Conformance: The property can be specified in "VEVENT", "VTODO" or 6223 "VJOURNAL" calendar component. 6225 Description: When a calendar component is created, its sequence 6226 number is zero (US-ASCII decimal 48). It is monotonically incremented 6227 by the "Organizer's" CUA each time the "Organizer" makes a 6228 significant revision to the calendar component. When the "Organizer" 6229 makes changes to one of the following properties, the sequence number 6230 MUST be incremented: 6232 . "DTSTART" 6234 . "DTEND" 6236 . "DUE" 6238 . "RDATE" 6240 . "RRULE" 6242 . "EXDATE" 6244 . "EXRULE" 6246 . "STATUS" 6248 In addition, changes made by the "Organizer" to other properties can 6249 also force the sequence number to be incremented. The "Organizer" CUA 6250 MUST increment the sequence number when ever it makes changes to 6251 properties in the calendar component that the "Organizer" deems will 6252 jeopardize the validity of the participation status of the 6253 "Attendees". For example, changing the location of a meeting from one 6254 locale to another distant locale could effectively impact the 6255 participation status of the "Attendees". 6257 The "Organizer" includes this property in an iCalendar object that it 6258 sends to an "Attendee" to specify the current version of the calendar 6259 component. 6261 The "Attendee" includes this property in an iCalendar object that it 6262 sends to the "Organizer" to specify the version of the calendar 6263 component that the "Attendee" is referring to. 6265 A change to the sequence number is not the mechanism that an 6266 "Organizer" uses to request a response from the "Attendees". The 6267 "RSVP" parameter on the "ATTENDEE" property is used by the 6268 "Organizer" to indicate that a response from the "Attendees" is 6269 requested. 6271 Format Definition: This property is defined by the following 6272 notation: 6274 seq = "SEQUENCE" seqparam ":" integer CRLF 6275 ; Default is "0" 6277 seqparam = *(";" xparam) 6279 Example: The following is an example of this property for a calendar 6280 component that was just created by the "Organizer". 6282 SEQUENCE:0 6284 The following is an example of this property for a calendar component 6285 that has been revised two different times by the "Organizer". 6287 SEQUENCE:2 6289 4.8.8 Miscellaneous Component Properties 6291 The following properties specify information about a number of 6292 miscellaneous features of calendar components. 6294 4.8.8.1 Non-standard Properties 6296 Property Name: Any property name with a "X-" prefix 6298 Purpose: This class of property provides a framework for defining 6299 non-standard properties. 6301 Value Type: TEXT 6303 Property Parameters: Non-standard and language property parameters 6304 can be specified on this property. 6306 Conformance: This property can be specified in any calendar 6307 component. 6309 Description: The MIME Calendaring and Scheduling Content Type 6310 provides a "standard mechanism for doing non-standard things". This 6311 extension support is provided for implementers to "push the envelope" 6312 on the existing version of the memo. Extension properties are 6313 specified by property and/or property parameter names that have the 6314 prefix text of "X-" (the two character sequence: LATIN CAPITAL LETTER 6315 X character followed by the HYPEN-MINUS character). It is recommended 6316 that vendors concatenate onto this sentinel another short prefix text 6317 to identify the vendor. This will facilitate readability of the 6318 extensions and minimize possible collision of names between different 6319 vendors. User agents that support this content type are expected to 6320 be able to parse the extension properties and property parameters but 6321 can ignore them. 6323 At present, there is no registration authority for names of extension 6324 properties and property parameters. The data type for this property 6325 is TEXT. Optionally, the data type can be any of the other valid data 6326 types. 6328 Format Definition: The property is defined by the following notation: 6330 x-prop = x-name *(";" xparam) [";" languageparam] ":" text CRLF 6331 ; Lines longer than 75 octets should be folded 6333 Example: The following might be the ABC vendor's extension for an 6334 audio-clip form of subject property: 6336 X-ABC-MMSUBJ;X-ABC-MMSUBJTYPE=wave:http://load.noise.org/mysubj.wav 6338 4.8.8.2 Request Status 6340 Property Name: REQUEST-STATUS 6342 Purpose: This property defines the status code returned for a 6343 scheduling request. 6345 Value Type: TEXT 6347 Property Parameters: Non-standard and language property parameters 6348 can be specified on this property. 6350 Conformance: The property can be specified in "VEVENT", "VTODO", 6351 "VJOURNAL" or "VFREEBUSY" calendar component. 6353 Description: This property is used to return status code information 6354 related to the processing of an associated iCalendar object. The data 6355 type for this property is TEXT. 6357 The value consists of a short return status component, a longer 6358 return status description component, and optionally a status-specific 6359 data component. The components of the value are separated by the 6360 SEMICOLON character (US-ASCII decimal 59). 6362 The short return status is a PERIOD character (US-ASCII decimal 46) 6363 separated 3-tuple of integers. For example, "3.1.1". The successive 6364 levels of integers provide for a successive level of status code 6365 granularity. 6367 The following are initial classes for the return status code. 6368 Individual iCalendar object methods will define specific return 6369 status codes for these classes. In addition, other classes for the 6370 return status code may be defined using the registration process 6371 defined later in this memo. 6373 |==============+===============================================| 6374 | Short Return | Longer Return Status Description | 6375 | Status Code | | 6376 |==============+===============================================| 6377 | 1.xx | Preliminary success. This class of status | 6378 | | of status code indicates that the request has | 6379 | | request has been initially processed but that | 6380 | | completion is pending. | 6381 |==============+===============================================| 6382 | 2.xx | Successful. This class of status code | 6383 | | indicates that the request was completed | 6384 | | successfuly. However, the exact status code | 6385 | | can indicate that a fallback has been taken. | 6386 |==============+===============================================| 6387 | 3.xx | Client Error. This class of status code | 6388 | | indicates that the request was not successful.| 6389 | | The error is the result of either a syntax or | 6390 | | a semantic error in the client formatted | 6391 | | request. Request should not be retried until | 6392 | | the condition in the request is corrected. | 6393 |==============+===============================================| 6394 | 4.xx | Scheduling Error. This class of status code | 6395 | | indicates that the request was not successful.| 6396 | | Some sort of error occurred within the | 6397 | | calendaring and scheduling service, not | 6398 | | directly related to the request itself. | 6399 |==============+===============================================| 6401 Format Definition: The property is defined by the following notation: 6403 rstatus = "REQUEST-STATUS" rstatparam ":" 6404 statcode ";" statdesc [";" extdata] 6406 rstatparam = *( 6408 ; the following is optional, 6409 ; but MUST NOT occur more than once 6411 (";" languageparm) / 6413 ; the following is optional, 6414 ; and MAY occur more than once 6416 (";" xparam) 6417 ) 6419 statcode = 1*DIGIT *("." 1*DIGIT) 6420 ;Hierarchical, numeric return status code 6422 statdesc = text 6423 ;Textual status description 6425 extdata = text 6426 ;Textual exception data. For example, the offending property 6427 ;name and value or complete property line. 6429 Example: The following are some possible examples of this property. 6430 The COMMA and SEMICOLON separator characters in the property value 6431 are BACKSLASH character escaped because they appear in a text value. 6433 REQUEST-STATUS:2.0;Success 6435 REQUEST-STATUS:3.1;Invalid property value;DTSTART:96-Apr-01 6437 REQUEST-STATUS:2.8; Success\, repeating event ignored. Scheduled 6438 as a single event.;RRULE:FREQ=WEEKLY\;INTERVAL=2 6440 REQUEST-STATUS:4.1;Event conflict. Date/time is busy. 6442 REQUEST-STATUS:3.7;Invalid calendar user;ATTENDEE: 6443 MAILTO:jsmith@host.com 6445 5 iCalendar Object Examples 6447 The following examples are provided as an informational source of 6448 illustrative iCalendar objects consistent with this content type. 6450 The following example specifies a three-day conference that begins at 6451 8:00 AM EDT, September 18, 1996 and end at 6:00 PM EDT, September 20, 6452 1996. 6454 BEGIN:VCALENDAR 6455 PRODID:-//xyz Corp//NONSGML PDA Calendar Verson 1.0//EN 6456 VERSION:2.0 6457 BEGIN:VEVENT 6458 DTSTAMP:19960704T120000Z 6459 UID:uid1@host.com 6460 ORGANIZER:MAILTO:jsmith@host.com 6461 DTSTART:19960918T143000Z 6462 DTEND:19960920T220000Z 6463 STATUS:CONFIRMED 6464 CATEGORIES:CONFERENCE 6465 SUMMARY:Networld+Interop Conference 6466 DESCRIPTION:Networld+Interop Conference 6467 and Exhibit\nAtlanta World Congress Center\n 6468 Atlanta, Georgia 6469 END:VEVENT 6470 END:VCALENDAR 6471 The following example specifies a group scheduled meeting that begin 6472 at 8:30 AM EST on March 12, 1998 and end at 9:30 AM EST on March 12, 6473 1998. The "Organizer" has scheduled the meeting with one or more 6474 calendar users in a group. A time zone specification for Eastern 6475 United States has been specified. 6477 BEGIN:VCALENDAR 6478 PRODID:-//RDU Software//NONSGML HandCal//EN 6479 VERSION:2.0 6480 BEGIN:VTIMEZONE 6481 TZID:US-Eastern 6482 BEGIN:STANDARD 6483 DTSTART:19981025T020000 6484 RDATE:19981025T020000 6485 TZOFFSETFROM:-0400 6486 TZOFFSETTO:-0500 6487 TZNAME:EST 6488 END:STANDARD 6489 BEGIN:DAYLIGHT 6490 DTSTART:19990404T020000 6491 RDATE:19990404T020000 6492 TZOFFSETFROM:-0500 6493 TZOFFSETTO:-0400 6494 TZNAME:EDT 6495 END:DAYLIGHT 6496 END:VTIMEZONE 6497 BEGIN:VEVENT 6498 DTSTAMP:19980309T231000Z 6499 UID:guid-1.host1.com 6500 ORGANIZER;ROLE=CHAIR:MAILTO:mrbig@host.com 6501 ATTENDEE;RSVP=TRUE;ROLE=REQ-PARTICIPANT;CUTYPE=GROUP: 6502 MAILTO:employee-A@host.com 6503 DESCRIPTION:Project XYZ Review Meeting 6504 CATEGORIES:MEETING 6505 CLASS:PUBLIC 6506 CREATED:19980309T130000Z 6507 SUMMARY:XYZ Project Review 6508 DTSTART;TZID=US-Eastern:19980312T083000 6509 DTEND;TZID=US-Eastern:19980312T093000 6510 LOCATION:1CP Conference Room 4350 6511 END:VEVENT 6512 END:VCALENDAR 6514 The following is an example of an iCalendar object passed in a MIME 6515 message with a single body part consisting of a "text/calendar" 6516 Content Type. 6518 TO:jsmith@host1.com 6519 FROM:jdoe@host1.com 6520 MIME-VERSION:1.0 6521 MESSAGE-ID: 6522 CONTENT-TYPE:text/calendar 6523 BEGIN:VCALENDAR 6524 METHOD:xyz 6525 VERSION:2.0 6526 PRODID:-//ABC Corporation//NONSGML My Product//EN 6527 BEGIN:VEVENT 6528 DTSTAMP:19970324T1200Z 6529 SEQUENCE:0 6530 UID:uid3@host1.com 6531 ORGANIZER:MAILTO:jdoe@host1.com 6532 ATTENDEE;RSVP=TRUE:MAILTO:jsmith@host1.com 6533 DTSTART:19970324T123000Z 6534 DTEND:19970324T210000Z 6535 CATEGORIES:MEETING,PROJECT 6536 CLASS:PUBLIC 6537 SUMMARY:Calendaring Interoperability Planning Meeting 6538 DESCRIPTION:Discuss how we can test c&s interoperability\n 6539 using iCalendar and other IETF standards. 6540 LOCATION:LDB Lobby 6541 ATTACH;FMTTYPE=application/postscript:ftp://xyzCorp.com/pub/ 6542 conf/bkgrnd.ps 6543 END:VEVENT 6544 END:VCALENDAR 6546 The following is an example of a to-do due on April 15, 1998. An 6547 audio alarm has been specified to remind the calendar user at noon, 6548 the day before the to-do is expected to be completed and repeat 6549 hourly, four additional times. The to-do definition has been modified 6550 twice since it was initially created. 6552 BEGIN:VCALENDAR 6553 VERSION:2.0 6554 PRODID:-//ABC Corporation//NONSGML My Product//EN 6555 BEGIN:VTODO 6556 DTSTAMP:19980130T134500Z 6557 SEQUENCE:2 6558 UID:uid4@host1.com 6559 ORGANIZER:MAILTO:unclesam@us.gov 6560 ATTENDEE;PARTSTAT=ACCEPTED:MAILTO:jqpublic@host.com 6561 DUE:19980415T235959 6562 STATUS:NEEDS-ACTION 6563 SUMMARY:Submit Income Taxes 6564 BEGIN:VALARM 6565 ACTION:AUDIO 6566 TRIGGER:19980403T120000 6567 ATTACH;FMTTYPE=audio/basic:http://host.com/pub/audio- 6568 files/ssbanner.aud 6569 REPEAT:4 6570 DURATION:PT1H 6571 END:VALARM 6572 END:VTODO 6573 END:VCALENDAR 6575 The following is an example of a journal entry. 6577 BEGIN:VCALENDAR 6578 VERSION:2.0 6579 PRODID:-//ABC Corporation//NONSGML My Product//EN 6580 BEGIN:VJOURNAL 6581 DTSTAMP:19970324T120000Z 6582 UID:uid5@host1.com 6583 ORGANIZER:MAILTO:jsmith@host.com 6584 STATUS:DRAFT 6585 CLASS:PUBLIC 6586 CATEGORY:Project Report, XYZ, Weekly Meeting 6587 DESCRIPTION:Project xyz Review Meeting Minutes\n 6588 Agenda\n1. Review of project version 1.0 requirements.\n2. 6589 Definition 6590 of project processes.\n3. Review of project schedule.\n 6591 Participants: John Smith, Jane Doe, Jim Dandy\n-It was 6592 decided that the requirements need to be signed off by 6593 product marketing.\n-Project processes were accepted.\n 6594 -Project schedule needs to account for scheduled holidays 6595 and employee vacation time. Check with HR for specific 6596 dates.\n-New schedule will be distributed by Friday.\n- 6597 Next weeks meeting is cancelled. No meeting until 3/23. 6598 END:VJOURNAL 6599 END:VCALENDAR 6601 The following is an example of published busy time information. The 6602 iCalendar object might be placed in the network resource 6603 www.host.com/calendar/busytime/jsmith.ifb. 6605 BEGIN:VCALENDAR 6606 VERSION:2.0 6607 PRODID:-//RDU Software//NONSGML HandCal//EN 6608 BEGIN:VFREEBUSY 6609 ORGANIZER:MAILTO:jsmith@host.com 6610 DTSTART:19980313T141711Z 6611 DTEND:19980410T141711Z 6612 FREEBUSY:19980314T233000Z/19980315T003000Z 6613 FREEBUSY:19980316T153000Z/19980316T163000Z 6614 FREEBUSY:19980318T030000Z/19980318T040000Z 6615 URL:http://www.host.com/calendar/busytime/jsmith.ifb 6616 END:VFREEBUSY 6617 END:VCALENDAR 6619 6 Recommended Practices 6621 These recommended practices should be followed in order to assure 6622 consistent handling of the following cases for an iCalendar object. 6624 1. Content lines longer than 75 octets SHOULD be folded. 6626 2. A calendar entry with a "DTSTART" property but no "DTEND" property 6627 does not take up any time. It is intended to represent an event 6628 that is associated with a given calendar date and time of day, 6629 such as an anniversary. Since the event does not take up any time, 6630 it MUST NOT be used to record busy time no matter what the value 6631 for the "TRANSP" property. 6633 3. When the "DTSTART" and "DTEND", for "VEVENT", "VJOURNAL" and 6634 "VFREEBUSY" calendar components, and "DTSTART" and "DUE", for 6635 "VTODO" calendar components, have the same value data type (e.g., 6636 DATE-TIME), they SHOULD specify values in the same time format 6637 (e.g., UTC time format). 6639 4. When the combination of the "RRULE" and "RDATE" properties on an 6640 iCalendar object produces multiple instances having the same start 6641 date/time, they should be collapsed to, and considered as, a 6642 single instance. 6644 5. When a calendar user receives multiple requests for the same 6645 calendar component (e.g., REQUEST for a "VEVENT" calendar 6646 component) as a result of being on multiple mailing lists 6647 specified by "ATTENDEE" properties in the request, they SHOULD 6648 respond to only one of the requests. The calendar user SHOULD also 6649 specify (using the "MEMBER" parameter of the "ATTENDEE" property) 6650 which mailing list they are a member of. 6652 6. An implementation can truncate a "SUMMARY" property value to 255 6653 characters. 6655 7. If seconds of the minute are not supported by an implementation, 6656 then a value of "00" SHOULD be specified for the seconds component 6657 in a time value. 6659 8. If the value type parameter (VALUE=) contains an unknown value 6660 type, it SHOULD be treated as TEXT. 6662 9. TZURL values SHOULD NOT be specified as a FILE URI type. This URI 6663 form can be useful within an organization, but is problematic in 6664 the Internet. 6666 10. Some possible English values for CATEGORIES property include 6667 "ANNIVERSARY", "APPOINTMENT", "BUSINESS", "EDUCATION", "HOLIDAY", 6668 "MEETING", "MISCELLANEOUS", "NON-WORKING HOURS", "NOT IN OFFICE", 6669 "PERSONAL", "PHONE CALL", "SICK DAY", "SPECIAL OCCASION", 6670 "TRAVEL", "VACATION". Categories can be specified in any 6671 registered language. 6673 11. Some possible English values for RESOURCES property include 6674 "CATERING", "CHAIRS", "COMPUTER PROJECTOR", "EASEL", "OVERHEAD 6675 PROJECTOR", "SPEAKER PHONE", "TABLE", "TV", "VCR", "VIDEO PHONE", 6676 "VEHICLE". Resources can be specified in any registered language. 6678 7 Registration of Content Type Elements 6680 This section provides the process for registration of MIME 6681 Calendaring and Scheduling Content Type iCalendar object methods and 6682 new or modified properties. 6684 7.1 Registration of New and Modified iCalendar Object Methods 6686 New MIME Calendaring and Scheduling Content Type iCalendar object 6687 methods are registered by the publication of an IETF Request for 6688 Comment (RFC). Changes to an iCalendar object method are registered 6689 by the publication of a revision of the RFC defining the method. 6691 7.2 Registration of New Properties 6693 This section defines procedures by which new properties or enumerated 6694 property values for the MIME Calendaring and Scheduling Content Type 6695 can be registered with the IANA. Non-IANA properties can be used by 6696 bilateral agreement, provided the associated properties names follow 6697 the "X-" convention. 6699 The procedures defined here are designed to allow public comment and 6700 review of new properties, while posing only a small impediment to the 6701 definition of new properties. 6703 Registration of a new property is accomplished by the following 6704 steps. 6706 7.2.1 Define the property 6708 A property is defined by completing the following template. 6710 To: ietf-calendar@imc.org 6712 Subject: Registration of text/calendar MIME property XXX 6714 Property name: 6716 Property purpose: 6718 Property value type(s): 6720 Property parameter (s): 6722 Conformance: 6724 Description: 6726 Format definition: 6728 Examples: 6730 The meaning of each field in the template is as follows. 6732 Property name: The name of the property, as it will appear in the 6733 body of an text/calendar MIME Content-Type "property: value" line to 6734 the left of the colon ":". 6736 Property purpose: The purpose of the property (e.g., to indicate a 6737 delegate for the event or to-do, etc.). Give a short but clear 6738 description. 6740 Property value type (s): Any of the valid value types for the 6741 property value needs to be specified. The default value type also 6742 needs to be specified. If a new value type is specified, it needs to 6743 be declared in this section. 6745 Property parameter (s): Any of the valid property parameters for the 6746 property needs to be specified. 6748 Conformance: The calendar components that the property can appear in 6749 needs to be specified. 6751 Description: Any special notes about the property, how it is to be 6752 used, etc. 6754 Format definition: The ABNF for the property definition needs to be 6755 specified. 6757 Examples: One or more examples of instances of the property needs to 6758 be specified. 6760 7.2.2 Post the Property definition 6762 The property description MUST be posted to the new property 6763 discussion list, ietf-calendar@imc.org. 6765 7.2.3 Allow a comment period 6767 Discussion on the new property MUST be allowed to take place on the 6768 list for a minimum of two weeks. Consensus MUST be reached on the 6769 property before proceeding to the next step. 6771 7.2.4 Submit the property for approval 6773 Once the two-week comment period has elapsed, and the proposer is 6774 convinced consensus has been reached on the property, the 6775 registration application should be submitted to the Method Reviewer 6776 for approval. The Method Reviewer is appointed to the Application 6777 Area Directors and can either accept or reject the property 6778 registration. An accepted registration should be passed on by the 6779 Method Reviewer to the IANA for inclusion in the official IANA method 6780 registry. The registration can be rejected for any of the following 6781 reasons. 1) Insufficient comment period; 2) Consensus not reached; 3) 6782 Technical deficiencies raised on the list or elsewhere have not been 6783 addressed. The Method Reviewer's decision to reject a property can be 6784 appealed by the proposer to the IESG, or the objections raised can be 6785 addressed by the proposer and the property resubmitted. 6787 7.3 Property Change Control 6789 Existing properties can be changed using the same process by which 6790 they were registered. 6792 1. Define the change 6794 2. Post the change 6796 3. Allow a comment period 6798 4. Submit the property for approval 6800 Note that the original author or any other interested party can 6801 propose a change to an existing property, but that such changes 6802 should only be proposed when there are serious omissions or errors in 6803 the published memo. The Method Reviewer can object to a change if it 6804 is not backward compatible, but is not required to do so. 6806 Property definitions can never be deleted from the IANA registry, but 6807 properties which are no longer believed to be useful can be declared 6808 OBSOLETE by a change to their "intended use" field. 6810 8 References 6812 The following documents are referred to within this memo. 6814 [ICMS] "Internet Calendaring Model Specification", Internet-Draft, 6815 October 1997, ftp://ftp.ietf.org/internet-drafts/draft-ietf-calsch- 6816 mod-03.txt. 6818 [IMIP] "iCalendar Message-based Interoperability Protocol (IMIP)", 6819 Internet Draft, April 1998, http://www.imc.org/draft-ietf-calsch- 6820 imip-05.txt. 6822 [ITIP] "iCalendar Transport-Independent Interoperability Protocol 6823 (iTIP) : Scheduling Events, Busy Time, To-dos and Journal Entries ", 6824 Internet-Draft, April 1998, http://www.imc.org/draft-ietf-calsch- 6825 itip-05.txt. 6827 [ISO 8601] ISO 8601, "Data elements and interchange formats_ 6828 Information interchange--Representation of dates and times", 6829 International Organization for Standardization, June, 1988. This 6830 standard is also addressed by the Internet Draft document 6831 ftp://ds.internic.net/internet-drafts/draft-newman-datetime-00.txt. 6833 [ISO 9070] ISO/IEC 9070, "Information Technology_SGML Support 6834 Facilities--Registration Procedures for Public Text Owner 6835 Identifiers", Second Edition, International Organization for 6836 Standardization, April 1991. 6838 [MIME DIR] Howes, T., Smith, M., "A MIME Content-Type for Directory 6839 Information", Internet-draft-ietf-asid-mime-direct-07.txt, November 6840 1997. 6842 [RFC 822] Crocker, D., "Standard for the Format of ARPA Internet Text 6843 Messages", STD 11, RFC 822, August 1982. 6845 [RFC 1738] Berners-Lee, T., Masinter, L., McCahill, M., "Uniform 6846 Resource Locators (URL)", RFC 1738, December 1994. 6848 [RFC 1766] Alvestrand, H., "Tags for the Identification of 6849 Languages", March 1995. 6851 [RFC 2045] Freed, N., Borenstein, N., " Multipurpose Internet Mail 6852 Extensions (MIME) - Part One: Format of Internet Message Bodies", RFC 6853 2045, November 1996. 6855 [RFC 2046] Freed, N., Borenstein, N., " Multipurpose Internet Mail 6856 Extensions (MIME) - Part Two: Media Types", RFC 2046, November 1996. 6858 [RFC 2047] Moore, K., "Multipurpose Internet Mail Extensions (MIME) - 6859 Part Three: Message Header Extensions for Non-ASCII Text", RFC 2047, 6860 November 1996. 6862 [RFC 2048] Freed, N., J. Klensin, J. Postel, "Multipurpose Internet 6863 Mail Extensions (MIME) - Part Four: Registration Procedures", RFC 6864 2048, January 1997. 6866 [RFC 2111] "Content-ID and Message-ID Uniform Resource Locators", RFC 6867 2111, March 1997. 6869 [RFC 2119] "Key words for use in RFCs to Indicate Requirement 6870 Levels", RFC 2119, March 1997. 6872 [RFC 2234] Crocker, D., Overell, P., "Augmented BNF for Syntax 6873 Specifications: ABNF", RFC 2234, November 1997. 6875 [RFC 2279] "UTF-8, a transformation format of ISO 10646", RFC 2279, 6876 January 1998. 6878 [TZ] Olson, A.D., et al, Time zone code and data, 6879 ftp://elsie.nci.nih.gov/pub/, updated periodically. 6881 [VCARD] Internet Mail Consortium, "vCard - The Electronic Business 6882 Card Version 2.1", http://www.imc.org/pdi/vcard-21.txt, September 6883 18, 1996. 6885 [VCAL] Internet Mail Consortium, "vCalendar - The Electronic 6886 Calendaring and Scheduling Exchange Format", 6887 http://www.imc.org/pdi/vcal-10.txt, September 18, 1996. 6889 [XAPIA] "XAPIA CSA, Calendaring and Scheduling Application 6890 Programming Interface (CSA) Version 1.0", X.400 API Association, 6891 November 15, 1994. 6893 9 Acknowledgments 6895 A hearty thanks to the IETF Calendaring and Scheduling Working Group 6896 and also the following individuals who have participated in the 6897 drafting, review and discussion of this memo: 6899 Roland Alden, Harald T. Alvestrand, Eric Berman, Denis Bigorgne, John 6900 Binici, Bill Bliss, Philippe Boucher, Steve Carter, Andre 6901 Courtemanche, Dave Crocker, David Curley, Alec Dun, John Evans, Ross 6902 Finlayson, Randell Flint, Ned Freed, Patrik Faltstrom, Chuck 6903 Grandgent, Mark Handley, Steve Hanna, Paul B. Hill, Paul Hoffman, 6904 Ross Hopson, Mark Horton, Daryl Huff, Bruce Kahn, C. Harald Koch, 6905 Ryan Jansen, Don Lavange, Antoine Leca, Theodore Lorek, Steve 6906 Mansour, Skip Montanaro, Keith Moore, Cecil Murray, Chris Newman, 6907 John Noerenberg, Ralph Patterson, Pete Resnick, Keith Rhodes, Robert 6908 Ripberger, John Rose, Doug Royer, Andras Salamar, Ted Schuh, Vinod 6909 Seraphin, Derrick Shadel, Ken Shan, Andrew Shuman, Steve Silverberg, 6910 William P. Spencer, John Sun, Mark Towfiq, Yvonne Tso, Robert Visnov, 6911 James L. Weiner, Mike Weston, William Wyatt. 6913 10 Authors' and Chairs' Addresses 6915 The following address information is provided in a MIME-VCARD, 6916 Electronic Business Card, format. 6918 The authors of this draft are: 6920 BEGIN:VCARD 6921 VERSION:3.0 6922 N:Dawson;Frank 6923 FN:Frank Dawson 6924 ORG:Lotus Development Corporation 6925 ADR;WORK;POSTAL;PARCEL:;6544 Battleford Drive; 6926 Raleigh;NC;27613-3502;USA 6927 TEL;WORK;MSG:+1-919-676-9515 6928 TEL;WORK;FAX:+1-919-676-9564 6929 EMAIL;INTERNET;PREF:Frank_Dawson@Lotus.com 6930 EMAIL;INTERNET:fdawson@earthlink.net 6931 URL:http://home.earthlink.net/~fdawson 6932 END:VCARD 6934 BEGIN:VCARD 6935 VERSION:3.0 6936 N:Stenerson;Derik 6937 FN:Derik Stenerson 6938 ORG:Microsoft Corporation 6939 ADR;WORK;POSTAL;PARCEL:;One Microsoft Way; 6940 Redmond;WA;98052-6399;USA 6941 TEL;WORK;MSG:+1-425-936-5522 6942 TEL;WORK;FAX:+1-425-936-7329 6943 EMAIL;INTERNET:deriks@Microsoft.com 6944 END:VCARD 6945 The iCalendar object is a result of the work of the Internet 6946 Engineering Task Force Calendaring and Scheduling Working Group. The 6947 chairman of that working group is: 6949 BEGIN:VCARD 6950 VERSION:3.0 6951 N:Ganguly;Anik 6952 FN:Anik Ganguly 6953 ORG: Open Text Inc. 6954 ADR;WORK;POSTAL;PARCEL: 38777 West Six Mile Road;Suite 101; 6955 Livonia;MI; 48152;USA 6956 TEL;WORK;MSG:+1-734-542-5955 6957 EMAIL;INTERNET:ganguly@acm.org 6958 END:VCARD 6960 The co-chairman of that working group is: 6962 BEGIN:VCARD 6963 VERSION:3.0 6964 N:Moskowitz;Robert 6965 FN:Robert Moskowitz 6966 EMAIL;INTERNET:rgm-ietf@htt-consult.com 6967 END:VCARD 6969 11 Full Copyright Statement 6971 "Copyright (C) The Internet Society (1998). All Rights Reserved. 6973 This document and translations of it may be copied and furnished to 6974 others, and derivative works that comment on or otherwise explain it 6975 or assist in its implmentation may be prepared, copied, published and 6976 distributed, in whole or in part, without restriction of any kind, 6977 provided that the above copyright notice and this paragraph are 6978 included on all such copies and derivative works. However, this 6979 document itself may not be modified in any way, such as by removing 6980 the copyright notice or references to the Internet Society or other 6981 Internet organizations, except as needed for the purpose of 6982 developing Internet standards in which case the procedures for 6983 copyrights defined in the Internet Standards process MUST be 6984 followed, or as required to translate it into languages other than 6985 English. 6987 The limited permissions granted above are perpetual and will not be 6988 revoked by the Internet Society or its successors or assigns. 6990 This document and the information contained herein is provided on an 6991 "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING 6992 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING 6993 BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION 6994 HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF 6995 MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.