idnits 2.17.1 draft-ietf-calext-jscalendar-13.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (May 2, 2019) is 1821 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Looks like a reference, but probably isn't: '1' on line 2331 -- Looks like a reference, but probably isn't: '2' on line 2333 -- Looks like a reference, but probably isn't: '3' on line 2336 == Unused Reference: 'RFC7986' is defined on line 2302, but no explicit reference was found in the text Summary: 0 errors (**), 0 flaws (~~), 2 warnings (==), 4 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Calendaring extensions N. Jenkins 3 Internet-Draft R. Stepanek 4 Intended status: Standards Track FastMail 5 Expires: November 3, 2019 May 2, 2019 7 JSCalendar: A JSON representation of calendar data 8 draft-ietf-calext-jscalendar-13 10 Abstract 12 This specification defines a data model and JSON representation of 13 calendar data that can be used for storage and data exchange in a 14 calendaring and scheduling environment. It aims to be an alternative 15 to the widely deployed iCalendar data format and to be unambiguous, 16 extendable and simple to process. In contrast to the JSON-based jCal 17 format, it is not a direct mapping from iCalendar and expands 18 semantics where appropriate. 20 Status of This Memo 22 This Internet-Draft is submitted in full conformance with the 23 provisions of BCP 78 and BCP 79. 25 Internet-Drafts are working documents of the Internet Engineering 26 Task Force (IETF). Note that other groups may also distribute 27 working documents as Internet-Drafts. The list of current Internet- 28 Drafts is at https://datatracker.ietf.org/drafts/current/. 30 Internet-Drafts are draft documents valid for a maximum of six months 31 and may be updated, replaced, or obsoleted by other documents at any 32 time. It is inappropriate to use Internet-Drafts as reference 33 material or to cite them other than as "work in progress." 35 This Internet-Draft will expire on November 3, 2019. 37 Copyright Notice 39 Copyright (c) 2019 IETF Trust and the persons identified as the 40 document authors. All rights reserved. 42 This document is subject to BCP 78 and the IETF Trust's Legal 43 Provisions Relating to IETF Documents 44 (https://trustee.ietf.org/license-info) in effect on the date of 45 publication of this document. Please review these documents 46 carefully, as they describe your rights and restrictions with respect 47 to this document. Code Components extracted from this document must 48 include Simplified BSD License text as described in Section 4.e of 49 the Trust Legal Provisions and are provided without warranty as 50 described in the Simplified BSD License. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 55 1.1. Relation to the iCalendar format . . . . . . . . . . . . 4 56 1.2. Relation to the jCal format . . . . . . . . . . . . . . . 5 57 1.3. Notational Conventions . . . . . . . . . . . . . . . . . 5 58 2. JSCalendar objects . . . . . . . . . . . . . . . . . . . . . 5 59 2.1. JSEvent . . . . . . . . . . . . . . . . . . . . . . . . . 6 60 2.2. JSTask . . . . . . . . . . . . . . . . . . . . . . . . . 6 61 2.3. JSGroup . . . . . . . . . . . . . . . . . . . . . . . . . 6 62 3. Structure of JSCalendar objects . . . . . . . . . . . . . . . 6 63 3.1. Type signatures . . . . . . . . . . . . . . . . . . . . . 7 64 3.2. Data Types . . . . . . . . . . . . . . . . . . . . . . . 7 65 3.2.1. UTCDate . . . . . . . . . . . . . . . . . . . . . . . 7 66 3.2.2. LocalDate . . . . . . . . . . . . . . . . . . . . . . 7 67 3.2.3. Duration . . . . . . . . . . . . . . . . . . . . . . 8 68 3.2.4. PatchObject . . . . . . . . . . . . . . . . . . . . . 8 69 3.2.5. Identifiers . . . . . . . . . . . . . . . . . . . . . 9 70 3.2.6. Time Zones . . . . . . . . . . . . . . . . . . . . . 9 71 3.2.7. Normalization and equivalence . . . . . . . . . . . . 9 72 3.3. Custom property extensions and values . . . . . . . . . . 10 73 4. Common JSCalendar properties . . . . . . . . . . . . . . . . 10 74 4.1. Metadata properties . . . . . . . . . . . . . . . . . . . 10 75 4.1.1. @type . . . . . . . . . . . . . . . . . . . . . . . . 10 76 4.1.2. uid . . . . . . . . . . . . . . . . . . . . . . . . . 11 77 4.1.3. relatedTo . . . . . . . . . . . . . . . . . . . . . . 11 78 4.1.4. prodId . . . . . . . . . . . . . . . . . . . . . . . 12 79 4.1.5. created . . . . . . . . . . . . . . . . . . . . . . . 12 80 4.1.6. updated . . . . . . . . . . . . . . . . . . . . . . . 13 81 4.1.7. sequence . . . . . . . . . . . . . . . . . . . . . . 13 82 4.1.8. method . . . . . . . . . . . . . . . . . . . . . . . 13 83 4.2. What and where properties . . . . . . . . . . . . . . . . 13 84 4.2.1. title . . . . . . . . . . . . . . . . . . . . . . . . 13 85 4.2.2. description . . . . . . . . . . . . . . . . . . . . . 13 86 4.2.3. descriptionContentType . . . . . . . . . . . . . . . 13 87 4.2.4. locations . . . . . . . . . . . . . . . . . . . . . . 14 88 4.2.5. virtualLocations . . . . . . . . . . . . . . . . . . 15 89 4.2.6. links . . . . . . . . . . . . . . . . . . . . . . . . 15 90 4.2.7. locale . . . . . . . . . . . . . . . . . . . . . . . 16 91 4.2.8. keywords . . . . . . . . . . . . . . . . . . . . . . 16 92 4.2.9. categories . . . . . . . . . . . . . . . . . . . . . 17 93 4.2.10. color . . . . . . . . . . . . . . . . . . . . . . . . 17 94 4.3. Recurrence properties . . . . . . . . . . . . . . . . . . 17 95 4.3.1. recurrenceRule . . . . . . . . . . . . . . . . . . . 17 96 4.3.2. recurrenceOverrides . . . . . . . . . . . . . . . . . 23 97 4.3.3. excluded . . . . . . . . . . . . . . . . . . . . . . 24 98 4.4. Sharing and scheduling properties . . . . . . . . . . . . 24 99 4.4.1. priority . . . . . . . . . . . . . . . . . . . . . . 24 100 4.4.2. freeBusyStatus . . . . . . . . . . . . . . . . . . . 25 101 4.4.3. privacy . . . . . . . . . . . . . . . . . . . . . . . 25 102 4.4.4. replyTo . . . . . . . . . . . . . . . . . . . . . . . 26 103 4.4.5. participants . . . . . . . . . . . . . . . . . . . . 26 104 4.5. Alerts properties . . . . . . . . . . . . . . . . . . . . 30 105 4.5.1. useDefaultAlerts . . . . . . . . . . . . . . . . . . 30 106 4.5.2. alerts . . . . . . . . . . . . . . . . . . . . . . . 30 107 4.6. Multilingual properties . . . . . . . . . . . . . . . . . 32 108 4.6.1. localizations . . . . . . . . . . . . . . . . . . . . 32 109 4.7. Time zone properties . . . . . . . . . . . . . . . . . . 33 110 4.7.1. timeZones . . . . . . . . . . . . . . . . . . . . . . 33 111 5. Type-specific JSCalendar properties . . . . . . . . . . . . . 34 112 5.1. JSEvent properties . . . . . . . . . . . . . . . . . . . 34 113 5.1.1. start . . . . . . . . . . . . . . . . . . . . . . . . 35 114 5.1.2. timeZone . . . . . . . . . . . . . . . . . . . . . . 35 115 5.1.3. duration . . . . . . . . . . . . . . . . . . . . . . 35 116 5.1.4. isAllDay . . . . . . . . . . . . . . . . . . . . . . 35 117 5.1.5. status . . . . . . . . . . . . . . . . . . . . . . . 36 118 5.2. JSTask properties . . . . . . . . . . . . . . . . . . . . 36 119 5.2.1. due . . . . . . . . . . . . . . . . . . . . . . . . . 36 120 5.2.2. start . . . . . . . . . . . . . . . . . . . . . . . . 36 121 5.2.3. timeZone . . . . . . . . . . . . . . . . . . . . . . 36 122 5.2.4. estimatedDuration . . . . . . . . . . . . . . . . . . 37 123 5.2.5. statusUpdatedAt . . . . . . . . . . . . . . . . . . . 37 124 5.2.6. isAllDay . . . . . . . . . . . . . . . . . . . . . . 37 125 5.2.7. progress . . . . . . . . . . . . . . . . . . . . . . 37 126 5.2.8. status . . . . . . . . . . . . . . . . . . . . . . . 38 127 5.3. JSGroup properties . . . . . . . . . . . . . . . . . . . 39 128 5.3.1. entries . . . . . . . . . . . . . . . . . . . . . . . 39 129 5.3.2. source . . . . . . . . . . . . . . . . . . . . . . . 39 130 6. JSCalendar object examples . . . . . . . . . . . . . . . . . 40 131 6.1. Simple event . . . . . . . . . . . . . . . . . . . . . . 40 132 6.2. Simple task . . . . . . . . . . . . . . . . . . . . . . . 40 133 6.3. Simple group . . . . . . . . . . . . . . . . . . . . . . 40 134 6.4. All-day event . . . . . . . . . . . . . . . . . . . . . . 41 135 6.5. Task with a due date . . . . . . . . . . . . . . . . . . 41 136 6.6. Event with end time-zone . . . . . . . . . . . . . . . . 42 137 6.7. Floating-time event (with recurrence) . . . . . . . . . . 42 138 6.8. Event with multiple locations and localization . . . . . 43 139 6.9. Recurring event with overrides . . . . . . . . . . . . . 44 140 6.10. Recurring event with participants . . . . . . . . . . . . 45 141 7. Security Considerations . . . . . . . . . . . . . . . . . . . 47 142 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 47 143 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 48 144 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 48 145 10.1. Normative References . . . . . . . . . . . . . . . . . . 48 146 10.2. Informative References . . . . . . . . . . . . . . . . . 50 147 10.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 51 148 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 51 150 1. Introduction 152 This document defines a data model for calendar event and task 153 objects, or groups of such objects, in electronic calendar 154 applications and systems. It aims to be unambiguous, extendable and 155 simple to process. 157 The key design considerations for this data model are as follows: 159 o The attributes of the calendar entry represented must be described 160 as a simple key-value pair, reducing complexity of its 161 representation. 163 o The data model should avoid all ambiguities and make it difficult 164 to make mistakes during implementation. 166 o Most of the initial set of attributes should be taken from the 167 iCalendar data format ([RFC5545], also see Section 1.1), but the 168 specification should add new attributes or value types, or not 169 support existing ones, where appropriate. Conversion between the 170 data formats need not fully preserve semantic meaning. 172 o Extensions, such as new properties and components, MUST NOT lead 173 to requiring an update to this document. 175 The representation of this data model is defined in the I-JSON format 176 [RFC7493], which is a strict subset of the JavaScript Object Notation 177 (JSON) Data Interchange Format [RFC8259]. Using JSON is mostly a 178 pragmatic choice: its widespread use makes JSCalendar easier to 179 adopt, and the ready availability of production-ready JSON 180 implementations eliminates a whole category of parser-related 181 interoperability issues. 183 1.1. Relation to the iCalendar format 185 The iCalendar data format [RFC5545], a widely deployed interchange 186 format for calendaring and scheduling data, has served calendaring 187 vendors for a long while, but contains some ambiguities and pitfalls 188 that can not be overcome without backward-incompatible changes. 190 For example, iCalendar defines various formats for local times, UTC 191 time and dates, which confuses new users. Other sources for errors 192 are the requirement for custom time zone definitions within a single 193 calendar component, as well as the iCalendar format itself; the 194 latter causing interoperability issues due to misuse of CR LF 195 terminated strings, line continuations and subtle differences between 196 iCalendar parsers. Lastly, up until recently the iCalendar format 197 did not have a way to express a concise difference between two 198 calendar components, which results in verbose exchanges during 199 scheduling. 201 1.2. Relation to the jCal format 203 The JSON format for iCalendar data, jCal [RFC7265], is a direct 204 mapping between iCalendar and JSON. It does not attempt to extend or 205 update iCalendar semantics, and consequently does not address the 206 issues outlined in Section 1.1. 208 Since the standardization of jCal, the majority of implementations 209 and service providers either kept using iCalendar, or came up with 210 their own proprietary JSON representation, which often are 211 incompatible with each other. JSCalendar is intended to meet this 212 demand for JSON formatted calendar data, and to provide a standard 213 representation as an alternative to new proprietary formats. 215 1.3. Notational Conventions 217 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 218 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 219 document are to be interpreted as described in [RFC2119]. 221 The underlying format used for this specification is JSON. 222 Consequently, the terms "object" and "array" as well as the four 223 primitive types (strings, numbers, booleans, and null) are to be 224 interpreted as described in Section 1 of [RFC8259]. 226 Some examples in this document contain "partial" JSON documents used 227 for illustrative purposes. In these examples, three periods "..." 228 are used to indicate a portion of the document that has been removed 229 for compactness. In this document, property and object definitions 230 are formatted like *this* and are referred to in other sections like 231 _this_. Verbatim text is formatted like "this". 233 2. JSCalendar objects 235 This section describes the calendar object types specified by 236 JSCalendar. 238 2.1. JSEvent 240 MIME type: "application/jscalendar+json;type=jsevent" 242 A JSEvent represents a scheduled amount of time on a calendar, 243 typically a meeting, appointment, reminder or anniversary. Multiple 244 participants may partake in the event at multiple locations. 246 The @type (Section 4.1.1) property value MUST be "jsevent". 248 2.2. JSTask 250 MIME type: "application/jscalendar+json;type=jstask" 252 A JSTask represents an action-item, assignment, to-do or work item . 254 The @type (Section 4.1.1) property value MUST be "jstask". 256 A JSTask may start and be due at certain points in time, may take 257 some estimated time to complete and may recur; none of which is 258 required. This notably differs from JSEvent (Section 2.1) which is 259 required to start at a certain point in time and typically takes some 260 non-zero duration to complete. 262 2.3. JSGroup 264 MIME type: "application/jscalendar+json;type=jsgroup" 266 A JSGroup is a collection of JSEvent (Section 2.1) and JSTask 267 (Section 2.2) objects. Typically, objects are grouped by topic (e.g. 268 by keywords) or calendar membership. 270 The @type (Section 4.1.1) property value MUST be "jsgroup". 272 3. Structure of JSCalendar objects 274 A JSCalendar object is a JSON object, which MUST be valid I-JSON (a 275 stricter subset of JSON), as specified in [RFC8259]. Property names 276 and values are case-sensitive. 278 The object has a collection of properties, as specified in the 279 following sections. Unless otherwise specified, all properties are 280 mandatory. Optional properties may have a default value, if 281 explicitly specified in the property definition. 283 3.1. Type signatures 285 Types signatures are given for all JSON objects in this document. 286 The following conventions are used: 288 o "Boolean|String": The value is either a JSON "Boolean" value, or a 289 JSON "String" value. 291 o "Foo": Any name that is not a native JSON type means an object for 292 which the properties (and their types) are defined elsewhere 293 within this document. 295 o "Foo[]": An array of objects of type "Foo". 297 o "String[Foo]": A JSON "Object" being used as a map (associative 298 array), where all the values are of type "Foo". 300 3.2. Data Types 302 In addition to the standard JSON data types, the following data types 303 are used in this specification: 305 3.2.1. UTCDate 307 This is a string in [RFC3339] "date-time" format, with the further 308 restrictions that any letters MUST be in upper-case, the time 309 component MUST be included and the time MUST be in UTC. Fractional 310 second values MUST NOT be included unless non-zero and MUST NOT have 311 trailing zeros, to ensure there is only a single representation for 312 each date-time. 314 For example "2010-10-10T10:10:10.003Z" is OK, but 315 "2010-10-10T10:10:10.000Z" is invalid and MUST be encoded as 316 "2010-10-10T10:10:10Z". 318 In common notation, it should be of the form "YYYY-MM-DDTHH:MM:SSZ". 320 3.2.2. LocalDate 322 This is a date-time string _with no time zone/offset information_. 323 It is otherwise in the same format as UTCDate: "YYYY-MM-DDTHH:MM:SS". 324 The time zone to associate the LocalDate with comes from an 325 associated property, or if no time zone is associated it defines 326 _floating time_. Floating date-times are not tied to any specific 327 time zone. Instead, they occur in every time zone at the same _wall- 328 clock_ time (as opposed to the same instant point in time). 330 3.2.3. Duration 332 A *Duration* is represented by a subset of ISO8601 duration format, 333 as specified by the following ABNF: 335 dur-secfrac = "." 1*DIGIT 336 dur-second = 1*DIGIT [dur-secfrac] "S" 337 dur-minute = 1*DIGIT "M" [dur-second] 338 dur-hour = 1*DIGIT "H" [dur-minute] 339 dur-time = "T" (dur-hour / dur-minute / dur-second) 340 dur-day = 1*DIGIT "D" 341 dur-week = 1*DIGIT "W" 343 duration = "P" (dur-day [dur-time] / dur-time / dur-week) 345 In addition, the duration MUST NOT include fractional second values 346 unless the fraction is non-zero. 348 A *SignedDuration* is represented as a duration, optionally preceeded 349 by a sign character. It typically is used to express the offset of a 350 point in time relative to an associated time. It is specified by the 351 following ABNF: 353 signed-duration = (["+"] / "-") duration 355 A negative sign indicates a point in time at or _before_ the 356 associated time, a positive or no sign a time at or _after_ the 357 associated time. 359 3.2.4. PatchObject 361 A *PatchObject* is of type "String[*|null]", and represents an 362 unordered set of patches on a JSON object. The keys are a path in a 363 subset of [RFC6901] JSON pointer format, with an implicit leading "/" 364 (i.e. prefix each key with "/" before applying the JSON pointer 365 evaluation algorithm). 367 A patch within a PatchObject is only valid, if all of the following 368 conditions apply: 370 1. The pointer MUST NOT reference inside an array (i.e. it MUST NOT 371 insert/delete from an array; the array MUST be replaced in its 372 entirety instead). 374 2. When evaluating a path, all parts prior to the last (i.e. the 375 value after the final slash) MUST exist. 377 3. There MUST NOT be two patches in the PatchObject where the 378 pointer of one is the prefix of the pointer of the other, e.g. 379 "alerts/foo/offset" and "alerts". 381 The value associated with each pointer is either: 383 o "null": Remove the property from the patched object. If not 384 present in the parent, this a no-op. 386 o Anything else: The value to replace the inherited property on the 387 patch object with (if present) or add to the property (if not 388 present). 390 Implementations MUST reject a PatchObject if any of its patches are 391 invalid. 393 3.2.5. Identifiers 395 If not stated otherwise in the respective property definition, 396 properties and object keys that define identifiers MUST be string 397 values, MUST be at least 1 character and maximum 256 characters in 398 size, and MUST only contain characters from the "URL and Filename 399 safe" Base 64 Alphabet, as defined in section 5 of [RFC4648]. This 400 is the ASCII alphanumeric characters (A-Za-z0-9), hyphen (-), and 401 underscore (_). Note that [RFC7493] requires string values be 402 encoded in UTF-8, so the maximum size of an identifier according to 403 this definition is 256 octets. 405 . Identifiers in object maps need not be universally unique, e.g. two 406 calendar objects MAY use the same identifiers in their respective 407 _links_ properties. 409 Nevertheless, a UUID typically is a good choice. 411 3.2.6. Time Zones 413 By default, time zones in JSCalendar are identified by their name in 414 the IANA Time Zone Database [1], and the zone rules of the respective 415 zone record apply. 417 Implementations MAY embed the definition of custom time zones in the 418 _timeZones_ property (see Section 4.7.1). 420 3.2.7. Normalization and equivalence 422 JSCalendar aims to provide unambiguous definitions for value types 423 and properties, but does not define a general normalization or 424 equivalence method for JSCalendar objects and types. This is because 425 the notion of equivalence might range from byte-level equivalence to 426 semantic equivalence, depending on the respective use case (for 427 example, the CalDAV protocol [RFC4791] requires octet equivalence of 428 the encoded calendar object to determine ETag equivalence). 430 Normalization of JSCalendar objects is hindered because of the 431 following reasons: 433 o Custom JSCalendar properties may contain arbitrary JSON values, 434 including arrays. However, equivalence of arrays might or might 435 not depend on the order of elements, depending on the respective 436 property definition. 438 o Several JSCalendar property values are defined as URIs and MIME 439 types, but normalization of these types is inherently protocol and 440 scheme-specific, depending on the use-case of the equivalence 441 definition (see section 6 of [RFC3986]). 443 Considering this, the definition of equivalence and normalization is 444 left to client and server implementations and to be negotiated by a 445 calendar exchange protocol or defined by another RFC. 447 3.3. Custom property extensions and values 449 Vendors MAY add additional properties to the calendar object to 450 support their custom features. The names of these properties MUST be 451 prefixed with a domain name controlled by the vendor to avoid 452 conflict, e.g. "example.com/customprop". 454 Some JSCalendar properties allow vendor-specific value extensions. 455 If so, vendor specific values MUST be prefixed with a domain name 456 controlled by the vendor, e.g. "example.com/customrel", unless 457 otherwise noted. 459 4. Common JSCalendar properties 461 This section describes the properties that are common to the various 462 JSCalendar object types. Specific JSCalendar object types may only 463 support a subset of these properties. The object type definitions in 464 Section 5 describe the set of supported properties per type. 466 4.1. Metadata properties 468 4.1.1. @type 470 Type: "String" 471 Specifies the type which this object represents. This MUST be one of 472 the following values, registered in a future RFC, or a vendor- 473 specific value: 475 o "jsevent": a JSCalendar event (Section 2.1). 477 o "jstask": a JSCalendar task (Section 2.2). 479 o "jsgroup": a JSCalendar group (Section 2.3). 481 A valid JSCalendar object MUST include this property. 483 4.1.2. uid 485 Type: "String" 487 A globally unique identifier, used to associate the object as the 488 same across different systems, calendars and views. The value of 489 this property MUST be unique across _all_ JSCalendar objects, even if 490 they are of different type. [RFC4122] describes a range of 491 established algorithms to generate universally unique identifiers 492 (UUID), and the random or pseudo-random version is recommended. 494 For compatibility with [RFC5545] UIDs, implementations MUST be able 495 to receive and persist values of at least 255 octets for this 496 property, but they MUST NOT truncate values in the middle of a UTF-8 497 multi-octet sequence. 499 A valid JSCalendar object MUST include this property. 501 4.1.3. relatedTo 503 Type: "String[Relation]" (optional) 505 Relates the object to other JSCalendar objects. This is represented 506 as a map of the UIDs of the related objects to information about the 507 relation. 509 A *Relation* object has the following properties: 511 o *relation*: "String[Boolean]" (optional) Describes how the linked 512 object is related to this object as a set of relation types. If 513 not null, the set MUST NOT be empty. 515 Keys in the set MUST be one of the following values, defined in a 516 future specification or a vendor-specific value: 518 * "first": The linked object is the first in the series this 519 object is part of. 521 * "next": The linked object is the next in the series this object 522 is part of. 524 * "child": The linked object is a subpart of this object. 526 * "parent": This object is part of the overall linked object. 528 The value for each key in the set MUST be "true". 530 If an object is split to make a "this and future" change to a 531 recurrence, the original object MUST be truncated to end at the 532 previous occurrence before this split, and a new object created to 533 represent all the objects after the split. A "next" relation MUST be 534 set on the original object's relatedTo property for the UID of the 535 new object. A "first" relation for the UID of the first object in 536 the series MUST be set on the new object. Clients can then follow 537 these UIDs to get the complete set of objects if the user wishes to 538 modify them all at once. 540 4.1.4. prodId 542 Type: "String" (optional) 544 The identifier for the product that created the JSCalendar object. 546 The vendor of the implementation SHOULD ensure that this is a 547 globally unique identifier, using some technique such as an FPI 548 value, as defined in [ISO.9070.1991]. It MUST only use characters of 549 an iCalendar TEXT data value (see section 3.3.11 in [RFC5545]). 551 This property SHOULD NOT be used to alter the interpretation of an 552 JSCalendar object beyond the semantics specified in this document. 553 For example, it is not to be used to further the understanding of 554 non-standard properties. 556 4.1.5. created 558 Type: "UTCDate" (optional) 560 The date and time this object was initially created. 562 4.1.6. updated 564 Type: "UTCDate" 566 The date and time the data in this object was last modified. 568 4.1.7. sequence 570 Type: "Number" (optional, default:"0") 572 Initially zero, this MUST be a non-negative integer that is 573 monotonically incremented each time a change is made to the object. 575 4.1.8. method 577 Type: "String" (optional) 579 The iTIP ([RFC5546]) method, in lower-case. Used for scheduling. 581 4.2. What and where properties 583 4.2.1. title 585 Type: "String" (optional, default:"") 587 A short summary of the object. 589 4.2.2. description 591 Type: "String" (optional, default:"") 593 A longer-form text description of the object. The content is 594 formatted according to the _descriptionContentType_ property. 596 4.2.3. descriptionContentType 598 Type: "String" (optional, default:"text/plain") 600 Describes the media type ([RFC6838]) of the contents of the 601 "description" property. Media types MUST be sub-types of type 602 "text", and SHOULD be "text/plain" or "text/html" ([MIME]). They MAY 603 define parameters and the "charset" parameter MUST be "utf-8", if 604 specified. Descriptions of type "text/html" MAY contain "cid" URLs 605 ([RFC2392]) to reference links in the calendar object by use of the 606 _cid_ property of the _Link_ object. 608 4.2.4. locations 610 Type: "String[Location]" (optional) 612 A map of location identifiers to Location objects, representing 613 locations associated with the object. 615 A *Location* object has the following properties. It must define at 616 least one other property than _relativeTo_. 618 o *name*: "String" (optional, default:"") The human-readable name of 619 the location. 621 o *description*: "String" (optional) Human-readable, plain-text 622 instructions for accessing this location. This may be an address, 623 set of directions, door access code, etc. 625 o *relativeTo*: "String" (optional) The relation type of this 626 location to the JSCalendar object. 628 This MUST be either one of the following values, registered in a 629 future RFC, or a vendor-specific value. Any value the client or 630 server doesn't understand should be treated the same as if this 631 property is omitted. 633 * "start": The JSCalendar object starts at this location. 635 * "end": The JSCalendar object ends at this location. 637 o *timeZone*: "String" (optional) A time zone for this location. 638 Also see Section 3.2.6. 640 o *coordinates*: "String" (optional) An [RFC5870] "geo:" URI for the 641 location. 643 o *linkIds*: "String[Boolean]" (optional) A set of link ids for 644 links to alternate representations of this location. Each key in 645 the set MUST be the identifier of a Link object defined in the 646 _links_ property of this calendar object. The value for each key 647 in the set MUST be "true". This MUST be omitted if none (rather 648 than an empty set). 650 For example, an alternative representation could be in vCard 651 format. 653 4.2.5. virtualLocations 655 Type: "String[VirtualLocation]" (optional) 657 A map of identifiers to VirtualLocation objects, representing virtual 658 locations, such as video conferences or chat rooms, associated with 659 the object. 661 A *VirtualLocation* object has the following properties. 663 o *name*: "String" (optional, default:"") The human-readable name of 664 the virtual location. 666 o *description*: "String" (optional) Human-readable plain-text 667 instructions for accessing this location. This may be an address, 668 set of directions, door access code, etc. 670 o *uri*: "String" A URI that represents how to connect to this 671 virtual location. 673 This may be a telephone number (represented as 674 "tel:+1-555-555-555") for a teleconference, a web address for 675 online chat, or any custom URI. 677 4.2.6. links 679 Type: "String[Link]" (optional) 681 A map of link identifiers to Link objects, representing external 682 resources associated with the object. 684 A *Link* object has the following properties: 686 o *href*: "String" A URI from which the resource may be fetched. 688 This MAY be a "data:" URL, but it is recommended that the file be 689 hosted on a server to avoid embedding arbitrarily large data in 690 JSCalendar object instances. 692 o *cid* "String" (optional) This MUST be a valid "content-id" value 693 according to the definition of section 2 in [RFC2392]. The 694 identifier MUST be unique within this JSCalendar object Link 695 objects but has no meaning beyond that. Specifically, it MAY be 696 different from the link identifier in the enclosing _links_ 697 property. 699 o *type*: "String" (optional) The content-type [RFC6838] of the 700 resource, if known. 702 o *size*: "Number" (optional) The size, in bytes, of the resource 703 when fully decoded (i.e. the number of bytes in the file the user 704 would download), if known. 706 o *rel*: "String" (optional) Identifies the relation of the linked 707 resource to the object. If set, the value MUST be a registered 708 relation type (see [RFC8288] and IANA Link Relations [2]). 710 Links with a rel of "enclosure" SHOULD be considered by the client 711 as attachments for download. 713 Links with a rel of "describedby" SHOULD be considered by the 714 client to be an alternate representation of the description. 716 Links with a rel of "icon" SHOULD be considered by the client to 717 be an image that it MAY use when presenting the calendar data to a 718 user. The _display_ property MAY be set to indicate the purpose 719 of this image. 721 o *display*: "String" (optional) Describes the intended purpose of a 722 link to an image. If set, the _rel_ property MUST be set to 723 "icon". The value MUST be either one of the following values, 724 registered in a future RFC, or a vendor-specific value: 726 * "badge": an image inline with the title of the object 728 * "graphic": a full image replacement for the object itself 730 * "fullsize": an image that is used to enhance the object 732 * "thumbnail": a smaller variant of "fullsize " to be used when 733 space for the image is constrained 735 o *title*: "String" (optional) A human-readable plain-text 736 description of the resource. 738 4.2.7. locale 740 Type: "String" (optional) 742 The [RFC5646] language tag that best describes the locale used for 743 the calendar object, if known. 745 4.2.8. keywords 747 Type: "String[Boolean]" (optional) 748 A set of keywords or tags that relate to the object. The set is 749 represented as a map, with the keys being the keywords. The value 750 for each key in the map MUST be "true". 752 4.2.9. categories 754 Type: "String[Boolean]" (optional) 756 A set of categories that relate to the calendar object. The set is 757 represented as a map, with the keys being the categories specified as 758 URIs. The value for each key in the map MUST be "true". 760 In contrast to _keywords_, categories typically are structured. For 761 example, a vendor owning the domain "example.com" might define the 762 categories "http://example.com/categories/sports/american-football"" 763 and "http://example.com/categories/music/r-b". 765 4.2.10. color 767 Type: "String" (optional) 769 Specifies a color clients MAY use when displaying this calendar 770 object. The value is a case-insensitive color name taken from the 771 CSS3 set of names, defined in Section 4.3 of W3C.REC- 772 css3-color-20110607 [3] or a CSS3 RGB color hex value. 774 4.3. Recurrence properties 776 4.3.1. recurrenceRule 778 Type: "Recurrence" (optional) 780 Defines a recurrence rule (repeating pattern) for recurring calendar 781 objects. 783 A *Recurrence* object is a JSON object mapping of a RECUR value type 784 in iCalendar, see [RFC5545] and[RFC7529]. A JSEvent recurs by 785 applying the recurrence rule (and _recurrenceOverrides_) to the 786 _start_ date/time. A JSTask recurs by applying the recurrence rule 787 (and _recurrenceOverrides_) to its _start_ date/time, if defined. If 788 the task does not define a start date-time, it recurs by its _due_ 789 date-time. If it neither defines a start or due date-time, it MUST 790 NOT define a _recurrenceRule_. 792 A Recurrence object has the following properties: 794 o *frequency*: "String" This MUST be one of the following values: 796 * "yearly" 798 * "monthly" 800 * "weekly" 802 * "daily" 804 * "hourly" 806 * "minutely" 808 * "secondly" 810 To convert from iCalendar, simply lower-case the FREQ part. 812 o *interval*: "Number" (optional, default:"1") The INTERVAL part 813 from iCalendar. If included, it MUST be an integer "x >= 1". 815 o *rscale*: "String" (optional, default:""gregorian"") The RSCALE 816 part from iCalendar RSCALE [RFC7529], converted to lower-case. 818 o *skip*: "String" (optional, default:""omit"") The SKIP part from 819 iCalendar RSCALE [RFC7529], converted to lower-case. 821 o *firstDayOfWeek*: "String" (optional, default:""mo"") The WKST 822 part from iCalendar, represented as a lower-case abbreviated two- 823 letter English day of the week. If included, it MUST be one of 824 the following values: ""mo"|"tu"|"we"|"th"|"fr"|"sa"|"su"". 826 o *byDay*: "NDay[]" (optional) An *NDay* object has the following 827 properties: 829 * *day*: "String" The day-of-the-week part of the BYDAY value in 830 iCalendar, lower-cased. MUST be one of the following values: 831 ""mo"|"tu"|"we"|"th"|"fr"|"sa"|"su"". 833 * *nthOfPeriod*: "Number" (optional) The ordinal part of the 834 BYDAY value in iCalendar (e.g. ""+1"" or ""-3""). If present, 835 rather than representing every occurrence of the weekday 836 defined in the _day_ property of this _NDay_, it represents 837 only a specific instance within the recurrence period. The 838 value can be positive or negative, but MUST NOT be zero. A 839 negative integer means nth-last of period. 841 o *byMonthDay*: "Number[]" (optional) The BYMONTHDAY part from 842 iCalendar. The array MUST have at least one entry if included. 844 o *byMonth*: "String[]" (optional) The BYMONTH part from iCalendar. 845 Each entry is a string representation of a number, starting from 846 "1" for the first month in the calendar (e.g. ""1" " means 847 ""January"" with Gregorian calendar), with an optional ""L"" 848 suffix (see [RFC7529]) for leap months (this MUST be upper-case, 849 e.g. ""3L""). The array MUST have at least one entry if included. 851 o *byYearDay*: "Number[]" (optional) The BYYEARDAY part from 852 iCalendar. The array MUST have at least one entry if included. 854 o *byWeekNo*: "Number[]" (optional) The BYWEEKNO part from 855 iCalendar. The array MUST have at least one entry if included. 857 o *byHour*: "Number[]" (optional) The BYHOUR part from iCalendar. 858 The array MUST have at least one entry if included. 860 o *byMinute*: "Number[]" (optional) The BYMINUTE part from 861 iCalendar. The array MUST have at least one entry if included. 863 o *bySecond*: "Number[]" (optional) The BYSECOND part from 864 iCalendar. The array MUST have at least one entry if included. 866 o *bySetPosition*: "Number[]" (optional) The BYSETPOS part from 867 iCalendar. The array MUST have at least one entry if included. 869 o *count*: "Number" (optional) The COUNT part from iCalendar. This 870 MUST NOT be included if an _until_ property is specified. 872 o *until*: "LocalDate" (optional) The UNTIL part from iCalendar. 873 This MUST NOT be included if a _count_ property is specified. 874 Note: if not specified otherwise for a specific JSCalendar object, 875 this date is presumed to be in the time zone specified in 876 _timeZone_. As in iCalendar, the until value bounds the 877 recurrence rule inclusively. To allow for using the same bound 878 regardless of the value of the _isAllDay_ property, the _until_ 879 date time MAY include non-zero time components even for all-day 880 calendar objects. 882 A recurrence rule specifies a set of set of date-times for recurring 883 calendar objects. A recurrence rule has the following semantics. 884 Note, wherever "year", "month" or "day of month" is used, this is 885 within the calendar system given by the "rscale" property, which 886 defaults to gregorian if omitted. 888 1. A set of candidates is generated. This is every second within a 889 period defined by the frequency property: 891 * *yearly*: every second from midnight on the 1st day of a year 892 (inclusive) to midnight the 1st day of the following year 893 (exclusive). 895 If skip is not "omit", the calendar system has leap months and 896 there is a byMonth property, generate candidates for the leap 897 months even if they don't occur in this year. 899 If skip is not "omit" and there is a byMonthDay property, 900 presume each month has the maximum number of days any month 901 may have in this calendar system when generating candidates, 902 even if it's more than this month actually has. 904 * *monthly*: every second from midnight on the 1st day of a 905 month (inclusive) to midnight on the 1st of the following 906 month (exclusive). 908 If skip is not "omit" and there is a byMonthDay property, 909 presume the month has the maximum number of days any month may 910 have in this calendar system when generating candidates, even 911 if it's more than this month actually has. 913 * *weekly*: every second from midnight (inclusive) on the first 914 day of the week (as defined by the firstDayOfWeek property, or 915 Monday if omitted), to midnight 7 days later (exclusive). 917 * *daily*: every second from midnight at the start of the day 918 (inclusive) to midnight at the end of the day (exclusive). 920 * *hourly*: every second from the beginning of the hour 921 (inclusive) to the beginning of the next hour (exclusive). 923 * *minutely*: every second from the beginning of the minute 924 (inclusive) to the beginning of the next minute (exclusive). 926 * *secondly*: the second itself, only. 928 2. Each date-time candidate is compared against all of the byX 929 properties of the rule except bySetPosition. If any property in 930 the rule does not match the date-time, it is eliminated. Each 931 byX property is an array; the date-time matches the property if 932 it matches any of the values in the array. The properties have 933 the following semantics: 935 * *byMonth*: the date-time is in the given month. 937 * *byWeekNo*: the date-time is in the nth week of the year. 938 Negative numbers mean the nth last week of the year. This 939 corresponds to weeks according to week numbering as defined in 940 ISO.8601.2004, with a week defined as a seven day period, 941 starting on the firstDayOfWeek property value or Monday if 942 omitted. Week number one of the calendar year is the first 943 week that contains at least four days in that calendar year. 945 If the date-time is not valid (this may happen when generating 946 candidates with a skip property in effect), it is always 947 eliminated by this property. 949 * *byYearDay*: the date-time is on the nth day of year. 950 Negative numbers mean the nth last day of the year. 952 If the date-time is not valid (this may happen when generating 953 candidates with a skip property in effect), it is always 954 eliminated by this property. 956 * *byMonthDay*: the date-time is on the given day of the month. 957 Negative numbers mean the nth last day of the month. 959 * *byDay*: the date-time is on the given day of the week. If 960 the day is prefixed by a number, it is the nth occurrence of 961 that day of the week within the month (if frequency is 962 monthly) or year (if frequency is yearly). Negative numbers 963 means nth last occurrence within that period. 965 * *byHour*: the date-time has the given hour value. 967 * *byMinute*: the date-time has the given minute value. 969 * *bySecond*: the date-time has the given second value. 971 If a skip property is defined and is not "omit", there may be 972 candidates that do not correspond to valid dates (e.g. 31st 973 Februrary in the gregorian calendar). In this case, the 974 properties MUST be considered in the order above and: 976 1. After applying the byMonth filter, if the candidate's month 977 is invalid for the given year increment it (if skip is 978 "forward") or decrement it (if skip is "backward") until a 979 valid month is found, incrementing/decrementing the year as 980 well if you pass through the beginning/end of the year. This 981 only applies to calendar systems with leap months. 983 2. After applying the byMonthDay filter, if the day of the month 984 is invalid for the given month and year, change the date to 985 the first day of the next month (if skip == "forward") or the 986 last day of the current month (if skip == "backward"). 988 3. If any valid date produced after applying the skip is already 989 a candidate, eliminate the duplicate. (For example after 990 adjusting, 30th Februrary and 31st February would both become 991 the same "real" date, so one is eliminated as a duplicate.) 993 3. If a bySetPosition property is included, this is now applied to 994 the ordered list of remaining dates (this property specifies the 995 indexes of date-times to keep; all others should be eliminated. 996 Negative numbers are indexes from the end of the list, with -1 997 being the last item). 999 4. Any date-times before the start date of the event are eliminated 1000 (see below for why this might be needed). 1002 5. If a skip property is included and is not "omit", eliminate any 1003 date-times that have already been produced by previous iterations 1004 of the algorithm. (This is not possible if skip == "omit".) 1006 6. If further dates are required (we have not reached the until 1007 date, or count limit) skip the next (interval - 1) sets of 1008 candidates, then continue from step 1. 1010 When determining the set of occurrence dates for an event or task, 1011 the following extra rules must be applied: 1013 1. The start date-time is always the first occurrence in the 1014 expansion (and is counted if the recurrence is limited by a 1015 "count" property), even if it would normally not match the rule. 1017 2. The first set of candidates to consider is that which would 1018 contain the start date-time. This means the first set may 1019 include candidates before the start; such candidates are 1020 eliminated from the results in step (4) as outlined before. 1022 3. The following properties MUST be implicitly added to the rule 1023 under the given conditions: 1025 * If frequency > "secondly" and no bySecond property: Add a 1026 bySecond property with the sole value being the seconds value 1027 of the start date-time. 1029 * If frequency > "minutely" and no byMinute property: Add a 1030 byMinute property with the sole value being the minutes value 1031 of the start date-time. 1033 * If frequency > "hourly" and no byHour property: Add a byHour 1034 property with the sole value being the hours value of the 1035 start date-time. 1037 * If frequency is "weekly" and no byDay property: Add a byDay 1038 property with the sole value being the day-of-the-week of the 1039 start date-time. 1041 * If frequency is "monthly" and no byDay property and no 1042 byMonthDay property: Add a byMonthDay property with the sole 1043 value being the day-of-the-month of the start date-time. 1045 * If frequency is "yearly" and no byYearDay property: 1047 + if there are no byMonth or byWeekNo properties, and either 1048 there is a byMonthDay property or there is no byDay 1049 property: Add a byMonth property with the sole value being 1050 the month of the start date-time. 1052 + if there is no byMonthDay, byWeekNo or byDay properties: 1053 Add a byMonthDay property with the sole value being the 1054 day-of-the-month of the start date-time. 1056 + if there is a byWeekNo property and no byMonthDay or byDay 1057 properties: Add a byDay property with the sole value being 1058 the day-of-the-week of the start date-time. 1060 4.3.2. recurrenceOverrides 1062 Type: "LocalDate[PatchObject]" (optional) 1064 A map of the recurrence-ids (the date-time of the start of the 1065 occurrence) to an object of patches to apply to the generated 1066 occurrence object. 1068 If the recurrence-id does not match an expanded start date from a 1069 recurrence rule, it is to be treated as an additional occurrence 1070 (like an RDATE from iCalendar). The patch object may often be empty 1071 in this case. 1073 If the patch object defines the _excluded_ property to be "true", 1074 then the recurring calendar object does not occur at the recurrence- 1075 id date-time (like an EXDATE from iCalendar). Such a patch object 1076 MUST NOT patch any other property. 1078 By default, an occurrence inherits all properties from the main 1079 object except the start (or due) date-time, which is shifted to the 1080 new start time of the LocalDate key. However, individual properties 1081 of the occurrence can be modified by a patch, or multiple patches. 1082 It is valid to patch the start property value, and this patch takes 1083 precedence over the LocalDate key. Both the LocalDate key as well as 1084 the patched start date-time may occur before the original JSCalendar 1085 object's start or due date. 1087 A pointer in the PatchObject MUST NOT start with one of the following 1088 prefixes; any patch with such a key MUST be ignored: 1090 o @type 1092 o uid 1094 o relatedTo 1096 o prodId 1098 o method 1100 o isAllDay 1102 o recurrenceRule 1104 o recurrenceOverrides 1106 o replyTo 1108 4.3.3. excluded 1110 Type: "Boolean" (optional, default:"false") 1112 Defines if this object is an overridden, excluded instance of a 1113 recurring JSCalendar object (also see Section 4.3.2). If this 1114 property value is "true", this calendar object instance MUST be 1115 removed from the occurrence expansion. 1117 4.4. Sharing and scheduling properties 1119 4.4.1. priority 1121 Type: "Number" (optional, default:"0") 1123 Specifies a priority for the calendar object. This may be used as 1124 part of scheduling systems to help resolve conflicts for a time 1125 period. 1127 The priority is specified as an integer in the range 0 to 9. A value 1128 of 0 specifies an undefined priority. A value of 1 is the highest 1129 priority. A value of 2 is the second highest priority. Subsequent 1130 numbers specify a decreasing ordinal priority. A value of 9 is the 1131 lowest priority. Other integer values are reserved for future use. 1133 4.4.2. freeBusyStatus 1135 Type: "String" (optional, default:"busy") 1137 Specifies how this property should be treated when calculating free- 1138 busy state. The value MUST be one of: 1140 o ""free"": The object should be ignored when calculating whether 1141 the user is busy. 1143 o ""busy"": The object should be included when calculating whether 1144 the user is busy. 1146 4.4.3. privacy 1148 Type: "String" (optional, default:"public") 1150 Calendar objects are normally collected together and may be shared 1151 with other users. The privacy property allows the object owner to 1152 indicate that it should not be shared, or should only have the time 1153 information shared but the details withheld. Enforcement of the 1154 restrictions indicated by this property are up to the 1155 implementations. 1157 This property MUST NOT affect the information sent to scheduled 1158 participants; it is only interpreted when the object is shared as 1159 part of a shared calendar. 1161 The value MUST be either one of the following values, registered in a 1162 future RFC, or a vendor-specific value. Vendor specific values MUST 1163 be prefixed with a domain name controlled by the vendor, e.g. 1164 "example.com/topsecret". Any value the client or server doesn't 1165 understand should be preserved but treated as equivalent to 1166 "private". 1168 o "public": The full details of the object are visible to those whom 1169 the object's calendar is shared with. 1171 o "private": The details of the object are hidden; only the basic 1172 time and metadata is shared. Implementations MUST ensure the 1173 following properties are stripped when the object is accessed by a 1174 sharee: 1176 * title 1178 * description 1180 * locations 1181 * links 1183 * locale 1185 * localizations 1187 * participants 1189 * replyTo 1191 In addition, any patches in "recurrenceOverrides" whose key is 1192 prefixed with one of the above properties MUST be stripped. 1194 o "secret": The object is hidden completely (as though it did not 1195 exist) when the calendar is shared. 1197 4.4.4. replyTo 1199 Type: "String[String]" (optional) 1201 Represents methods by which participants may submit their RSVP 1202 response to the organizer of the calendar object. The keys in the 1203 property value are the available methods and MUST only contain ASCII 1204 alphanumeric characters (A-Za-z0-9). The value is a URI to use that 1205 method. Future methods may be defined in future specifications; a 1206 calendar client MUST ignore any method it does not understand, but 1207 MUST preserve the method key and URI. This property MUST be omitted 1208 if no method is defined (rather than an empty object). If this 1209 property is set, the _participants_ property of this calendar object 1210 MUST contain at least one participant. 1212 The following methods are defined: 1214 o "imip": The organizer accepts an iMIP [RFC6047] response at this 1215 email address. The value MUST be a "mailto:" URI. 1217 o "web": Opening this URI in a web browser will provide the user 1218 with a page where they can submit a reply to the organizer. 1220 o "other": The organizer is identified by this URI but the method 1221 how to submit the RSVP is undefined. 1223 4.4.5. participants 1225 Type: "String[Participant]" (optional) 1227 A map of participant identifiers to participants, describing their 1228 participation in the calendar object. 1230 If this property is set, then the _replyTo_ property of this calendar 1231 object MUST define at least one reply method. 1233 A *Participant* object has the following properties: 1235 o *name*: "String" (optional) The display name of the participant 1236 (e.g. "Joe Bloggs"). 1238 o *email*: "String" (optional) The email address for the 1239 participant. 1241 o *sendTo*: "String[String]" Represents methods by which the 1242 participant may receive the invitation and updates to the calendar 1243 object. 1245 The keys in the property value are the available methods and MUST 1246 only contain ASCII alphanumeric characters (A-Za-z0-9). The value 1247 is a URI to use that method. Future methods may be defined in 1248 future specifications; a calendar client MUST ignore any method it 1249 does not understand, but MUST preserve the method key and URI. 1250 This property MUST be omitted if no method is defined (rather than 1251 an empty object). 1253 The following methods are defined: 1255 * "imip": The participant accepts an iMIP [RFC6047] request at 1256 this email address. The value MUST be a "mailto:" URI. It MAY 1257 be different from the value of the participant's _email_ 1258 property. 1260 * "other": The participant is identified by this URI but the 1261 method how to submit the invitation or update is undefined. 1263 o *kind*: "String" (optional) What kind of entity this participant 1264 is, if known. 1266 This MUST be either one of the following values, registered in a 1267 future RFC, or a vendor-specific value. Any value the client or 1268 server doesn't understand should be treated the same as if this 1269 property is omitted. 1271 * "individual": a single person 1273 * "group": a collection of people invited as a whole 1275 * "resource": a non-human resource, e.g. a projector 1276 * "location": a physical location involved in the calendar object 1277 that needs to be scheduled, e.g. a conference room. 1279 o *roles*: "String[Boolean]" A set of roles that this participant 1280 fulfills. 1282 At least one role MUST be specified for the participant. The keys 1283 in the set MUST be either one of the following values, registered 1284 in a future RFC, or a vendor-specific value: 1286 * "owner": The participant is an owner of the object. 1288 * "attendee": The participant is an attendee of the calendar 1289 object. 1291 * "chair": The participant is in charge of the calendar object 1292 when it occurs. 1294 The value for each key in the set MUST be "true". Roles that are 1295 unknown to the implementation MUST be preserved and MAY be 1296 ignored. 1298 o *locationId*: "String" (optional) The location at which this 1299 participant is expected to be attending. 1301 If the value does not correspond to any location id in the 1302 _locations_ property of the instance, this MUST be treated the 1303 same as if the participant's locationId were omitted. 1305 o *participationStatus*: "String" (optional, default:"needs-action") 1306 The participation status, if any, of this participant. 1308 The value MUST be either one of the following values, registered 1309 in a future RFC, or a vendor-specific value: 1311 * "needs-action": No status yet set by the participant. 1313 * "accepted": The invited participant will participate. 1315 * "declined": The invited participant will not participate. 1317 * "tentative": The invited participant may participate. 1319 o *attendance*: "String" (optional, default:"required") The required 1320 attendance of this participant. 1322 The value MUST be either one of the following values, registered 1323 in a future RFC, or a vendor-specific value. Any value the client 1324 or server doesn't understand should be treated the same as 1325 "required". 1327 * "none": Indicates a participant who is copied for information 1328 purposes only. 1330 * "optional": Indicates a participant whose attendance is 1331 optional. 1333 * "required": Indicates a participant whose attendance is 1334 required. 1336 o *expectReply*: "Boolean" (optional, default:"false") If true, the 1337 organizer is expecting the participant to notify them of their 1338 status. 1340 o *scheduleSequence*: "Number" (optional, default:"0") The sequence 1341 number of the last response from the participant. If defined, 1342 this MUST be a non-negative integer. 1344 This can be used to determine whether the participant has sent a 1345 new RSVP following significant changes to the calendar object, and 1346 to determine if future responses are responding to a current or 1347 older view of the data. 1349 o *scheduleUpdated*: "UTCDate" (optional) The _updated_ property of 1350 the last iMIP response from the participant. 1352 This can be compared to the _updated_ timestamp in future iMIP 1353 responses to determine if the response is older or newer than the 1354 current data. 1356 o *invitedBy*: "String" (optional) The participant id of the 1357 participant who invited this one, if known. 1359 o *delegatedTo*: "String[Boolean]" (optional) A set of participant 1360 ids that this participant has delegated their participation to. 1361 Each key in the set MUST be the identifier of a participant. The 1362 value for each key in the set MUST be "true". This MUST be 1363 omitted if none (rather than an empty set). 1365 o *delegatedFrom*: "String[Boolean]" (optional) A set of participant 1366 ids that this participant is acting as a delegate for. Each key 1367 in the set MUST be the identifier of a participant. The value for 1368 each key in the set MUST be "true". This MUST be omitted if none 1369 (rather than an empty set). 1371 o *memberOf*: "String[Boolean]" (optional) A set of group 1372 participants that were invited to this calendar object, which 1373 caused this participant to be invited due to their membership of 1374 the group(s). Each key in the set MUST be the identifier of a 1375 participant. The value for each key in the set MUST be "true". 1376 This MUST be omitted if none (rather than an empty set). 1378 o *linkIds*: "String[Boolean]" (optional) A set of links to more 1379 information about this participant, for example in vCard format. 1380 The keys in the set MUST be the identifier of a Link object in the 1381 calendar object's _links_ property. The value for each key in the 1382 set MUST be "true". This MUST be omitted if none (rather than an 1383 empty set). 1385 4.5. Alerts properties 1387 4.5.1. useDefaultAlerts 1389 Type: "Boolean" (optional, default:"false") 1391 If "true", use the user's default alerts and ignore the value of the 1392 _alerts_ property. Fetching user defaults is dependent on the API 1393 from which this JSCalendar object is being fetched, and is not 1394 defined in this specification. If an implementation cannot determine 1395 the user's default alerts, or none are set, it MUST process the 1396 alerts property as if useDefaultAlerts is set to "false". 1398 4.5.2. alerts 1400 Type: "String[Alert]" (optional) 1402 A map of alert identifiers to Alert objects, representing alerts/ 1403 reminders to display or send the user for this calendar object. 1405 An *Alert* Object has the following properties: 1407 o *trigger*: "OffsetTrigger|UnknownTrigger" Defines when to trigger 1408 the alert. 1410 An *OffsetTrigger* object has the following properties: 1412 * *type*: "String" The value of this property MUST be "offset". 1414 * *offset*: "SignedDuration" Defines to trigger the alert 1415 relative to the time property defined in the _relativeTo_ 1416 property. If the calendar object does not define a time zone, 1417 the user's default time zone SHOULD be used when determining 1418 the offset, if known. Otherwise, the time zone to use is 1419 implementation specific. 1421 * *relativeTo*: "String" (optional, default:"start") Specifies 1422 the time property which the alert _offset_ is relative to. The 1423 value MUST be one of: 1425 + "start": triggers the alert relative to the start of the 1426 calendar object 1428 + "end": triggers the alert relative to the end/due time of 1429 the calendar object 1431 An *UnknownTrigger* object is an object that contains a *type* 1432 property whose value is not "offset", plus zero or more other 1433 properties. This is for compatibility with client extensions and 1434 future RFCs. Implementations SHOULD NOT trigger for trigger types 1435 they do not understand, but MUST preserve them. 1437 o *acknowledged*: "UTCDate" (optional) 1439 When the user has permanently dismissed the alert the client MUST 1440 set this to the current time in UTC. Other clients which sync 1441 this property can then automatically dismiss or suppress duplicate 1442 alerts (alerts with the same alert id that triggered on or before 1443 this date-time). 1445 For a recurring calendar object, the _acknowledged_ property of 1446 the parent object MUST be updated, unless the alert is already 1447 overridden in _recurrenceOverrides_. 1449 o *snoozed*: "UTCDate" (optional) 1451 If the user temporarily dismisses the alert, this is the UTC date- 1452 time after which it should trigger again. Setting this property 1453 on an instance of a recurring calendar object MUST update the 1454 alarm on the master object, unless the respective instance already 1455 is defined in "recurrenceOverrides". It MUST NOT generate an 1456 override for the sole use of snoozing an alarm. 1458 o *action*: "String" (optional, default:"display") Describes how to 1459 alert the user. 1461 The value MUST be at most one of the following values, registered 1462 in a future RFC, or a vendor-specific value: 1464 * "display": The alert should be displayed as appropriate for the 1465 current device and user context. 1467 * "email": The alert should trigger an email sent out to the 1468 user, notifying about the alert. This action is typically only 1469 appropriate for server implementations. 1471 4.6. Multilingual properties 1473 4.6.1. localizations 1475 Type: "String[PatchObject]" (optional) 1477 A map of [RFC5646] language tags to patch objects, which localize the 1478 calendar object into the locale of the respective language tag. 1480 See the description of PatchObject (Section 3.2.4) for the structure 1481 of the PatchObject. The patches are applied to the top-level object. 1482 In addition to all the restrictions on patches specified there, the 1483 pointer also MUST NOT start with one of the following prefixes; any 1484 patch with a such a key MUST be ignored: 1486 o @type 1488 o due 1490 o duration 1492 o freeBusyStatus 1494 o localization 1496 o method 1498 o participants 1500 o prodId 1502 o progress 1504 o relatedTo 1506 o sequence 1508 o start 1510 o status 1512 o timeZone 1514 o uid 1515 o useDefaultAlerts 1517 Note that this specification does not define how to maintain validity 1518 of localized content. For example, a client application changing a 1519 JSCalendar object's title property might also need to update any 1520 localizations of this property. Client implementations SHOULD 1521 provide the means to manage localizations, but how to achieve this is 1522 specific to the application's workflow and requirements. 1524 4.7. Time zone properties 1526 4.7.1. timeZones 1528 Type: "String[TimeZone]" (optional) 1530 Maps identifiers of custom time zones to their time zone definition. 1531 The following restrictions apply for each key in the map: 1533 o It MUST start with the "/" character (ASCII decimal 47; also see 1534 sections 3.2.19 of [RFC5545] and 3.6. of [RFC7808] for discussion 1535 of the forward slash character in time zone identifiers). 1537 o It MUST be a valid _paramtext_ value as specified in section 3.1. 1538 of [RFC5545]. 1540 o At least one other property in the same JSCalendar object MUST 1541 reference a time zone using this identifier (i.e. orphaned time 1542 zones are not allowed). 1544 An identifier need only be unique to this JSCalendar object. 1546 A *TimeZone* object maps a VTIMEZONE component from iCalendar 1547 ([RFC5545]). A valid time zone MUST define at least one transition 1548 rule in the _standard_ or _daylight_ property. Its properties are: 1550 o *tzId*: "String" The TZID property from iCalendar. 1552 o *lastModified*: "UTCDate" (optional) The LAST-MODIFIED property 1553 from iCalendar. 1555 o *url*: "String" (optional) The TZURL property from iCalendar. 1557 o *validUntil*: "UTCDate" (optional) The TZUNTIL property from 1558 iCalendar specified in [RFC7808]. 1560 o *aliases*: "String[Boolean]" Maps the TZID-ALIAS-OF properties 1561 from iCalendar specified in [RFC7808] to a JSON set of aliases. 1563 The set is represented as an object, with the keys being the 1564 aliases. The value for each key in the set MUST be "true". 1566 o *standard*: "TimeZoneRule[]" (optional) The STANDARD sub- 1567 components from iCalendar. The order MUST be preserved during 1568 conversion. 1570 o *daylight*: "TimeZoneRule[]" (optional) The DAYLIGHT sub- 1571 components from iCalendar. The order MUST be preserved during 1572 conversion. 1574 A *TimeZoneRule* object maps a STANDARD or DAYLIGHT sub-component 1575 from iCalendar, with the restriction that _at most one_ recurrence 1576 rule is allowed per rule. It has the following properties: 1578 o *start*: "LocalDate" The DTSTART property from iCalendar. 1580 o *offsetTo*: "String" The TZOFFSETTO property from iCalendar. 1582 o *offsetFrom*: "String" The TZOFFSETFROM property from iCalendar. 1584 o *recurrenceRule*: "RecurrenceRule" (optional) The RRULE property 1585 mapped as specified in Section 4.3.1. During recurrence rule 1586 evaluation, the _until_ property value MUST be interpreted as a 1587 local time in the UTC time zone. 1589 o *recurrenceDates*: "LocalDate[Boolean]" (optional) Maps the RDATE 1590 properties from iCalendar to a JSON set. The set is represented 1591 as an object, with the keys being the recurrence dates. The value 1592 for each key in the set MUST be "true". 1594 o *names*: "String[Boolean]" (optional) Maps the TZNAME properties 1595 from iCalendar to a JSON set. The set is represented as an 1596 object, with the keys being the names. The value for each key in 1597 the set MUST be "true". 1599 o *comments*: "String[]" (optional) Maps the COMMENT properties from 1600 iCalendar. The order MUST be preserved during conversion. 1602 5. Type-specific JSCalendar properties 1604 5.1. JSEvent properties 1606 In addition to the common JSCalendar object properties (Section 4) a 1607 JSEvent has the following properties: 1609 5.1.1. start 1611 Type: "LocalDate" e.g. "2015-09-02T00:00:00" 1613 The date/time the event would start in the event's time zone. 1615 A valid JSEvent MUST include this property. 1617 5.1.2. timeZone 1619 Type: "String|null" (optional, default:"null") 1621 Identifies the time zone the event is scheduled in, or "null" for 1622 floating time. If omitted, this MUST be presumed to be "null" (i.e. 1623 floating time). Also see Section 3.2.6. 1625 5.1.3. duration 1627 Type: "Duration", e.g. "P2DT3H" (optional, default: "PT0S") 1629 The zero or positive duration of the event in the event's start time 1630 zone. The same rules as for the iCalendar DURATION value type 1631 ([RFC5545]) apply: The duration of a week or a day in hours/minutes/ 1632 seconds may vary if it overlaps a period of discontinuity in the 1633 event's time zone, for example a change from standard time to 1634 daylight-savings time. Leap seconds MUST NOT be considered when 1635 computing an exact duration. When computing an exact duration, the 1636 greatest order time components MUST be added first, that is, the 1637 number of days MUST be added first, followed by the number of hours, 1638 number of minutes, and number of seconds. Fractional seconds MUST be 1639 added last. 1641 A JSEvent MAY involve start and end locations that are in different 1642 time zones (e.g. a trans-continental flight). This can be expressed 1643 using the _relativeTo_ and _timeZone_ properties of the JSEvent's 1644 _location_ objects. 1646 5.1.4. isAllDay 1648 Type: "Boolean" (optional, default:"false") 1650 Specifies if the event is an all day event, such as a birthday or 1651 public holiday. 1653 If _isAllDay_ is true, then the following restrictions apply: 1655 o the _start_ property MUST have a time component of "T00:00:00". 1657 o the _timeZone_ property MUST be "null" 1659 o the _duration_ property MUST NOT include non-zero time components 1660 (hours, minutes, or seconds) 1662 o the _freeBusyStatus_ property MUST NOT be "busy" 1664 5.1.5. status 1666 Type: "String" (optional, default:"confirmed") 1668 The scheduling status (Section 4.4) of a JSEvent. If set, it MUST be 1669 one of: 1671 o "confirmed": Indicates the event is definite. 1673 o "cancelled": Indicates the event is cancelled. 1675 o "tentative": Indicates the event is tentative. 1677 5.2. JSTask properties 1679 In addition to the common JSCalendar object properties (Section 4) a 1680 JSTask has the following properties: 1682 5.2.1. due 1684 Type: "LocalDate" (optional) e.g. "2015-09-02T00:00:00" 1686 The date/time the task is due in the task's time zone. 1688 5.2.2. start 1690 Type: "LocalDate" (optional) e.g. "2015-09-02T00:00:00" 1692 The date/time the task should start in the task's time zone. 1694 5.2.3. timeZone 1696 Type: "String|null" (optional, default:"null") 1698 Identifies the time zone the task is scheduled in, or "null" for 1699 floating time. If omitted, this MUST be presumed to be "null" (i.e. 1700 floating time). Also see Section 3.2.6. 1702 5.2.4. estimatedDuration 1704 Type: "Duration" (optional), e.g. "P2DT3H" 1706 Specifies the estimated positive duration of time the task takes to 1707 complete. 1709 5.2.5. statusUpdatedAt 1711 Type: "UTCDate" (optional), e.g. "2016-06-13T12:00:00Z" 1713 Specifies the date/time the task status properties was last updated. 1715 If the task is recurring and has future instances, a client may want 1716 to keep track of the last status update timestamp of a specific task 1717 recurrence, but leave other instances unchanged. One way to achieve 1718 this is by overriding the statusUpdatedAt property in the task 1719 _recurrenceOverrides_. However, this could produce a long list of 1720 timestamps for regularly recurring tasks. An alternative approach is 1721 to split the JSTask into a current, single instance of JSTask with 1722 this instance status update time and a future recurring instance. 1723 Also see the definition of the _relatedTo_ on splitting. 1725 5.2.6. isAllDay 1727 Type: "Boolean" (optional, default:"false") 1729 Specifies if the task is an all day task. 1731 If _isAllDay_ is true, then the following restrictions apply: 1733 o the _start_ and _due_ properties MUST have a time component of 1734 "T00:00:00", or not be set 1736 o the _timeZone_ property MUST be "null" 1738 o the _freeBusyStatus_ property MUST NOT be "busy" 1740 5.2.7. progress 1742 In addition to the common properties of a _Participant_ object 1743 (Section 4.4.5), a Participant within a JSTask supports the following 1744 property: 1746 o *progress*: "ParticipantProgress" (optional) The progress of the 1747 participant for this task, if known. This property MUST NOT be 1748 set if the _participationStatus_ of this participant is any other 1749 value but "accepted". 1751 A *ParticipantProgress* object has the following properties: 1753 o *status*: "String" Describes the completion status of the 1754 participant's progress. 1756 The value MUST be at most one of the following values, registered 1757 in a future RFC, or a vendor-specific value: 1759 * "completed": The participant completed their task. 1761 * "in-process": The participant has started this task. 1763 * "failed": The participant failed to complete their task. 1765 o *timestamp*: "UTCDate" Describes the last time when the 1766 participant progress got updated. 1768 5.2.8. status 1770 Type: "String" 1772 Defines the overall status of this task. If omitted, the default 1773 status (Section 4.4) of a JSTask is defined as follows (in order of 1774 evaluation): 1776 o "completed": if all the _ParticipantProgress_ status of the task 1777 participants is "completed". 1779 o "failed": if at least one _ParticipantProgress_ status of the task 1780 participants is "failed". 1782 o "in-process": if at least one _ParticipantProgress_ status of the 1783 task participants is "in-process". 1785 o "needs-action": If none of the other criteria match. 1787 If set, it MUST be one of: 1789 o "needs-action": Indicates the task needs action. 1791 o "completed": Indicates the task is completed. 1793 o "in-process": Indicates the task is in process. 1795 o "cancelled": Indicates the task is cancelled. 1797 o "pending": Indicates the task has been created and accepted for 1798 processing, but not yet started. 1800 o "failed": Indicates the task failed. 1802 5.3. JSGroup properties 1804 JSGroup supports the following JSCalendar properties (Section 4): 1806 o @type 1808 o uid 1810 o created 1812 o updated 1814 o categories 1816 o keywords 1818 o name 1820 o description 1822 o color 1824 o links 1826 as well as the following JSGroup-specific properties: 1828 5.3.1. entries 1830 Type: "String[JSTask|JSEvent]" 1832 A collection of group members. This is represented as a map of the 1833 _uid_ property value to the JSCalendar object member having that uid. 1834 Implementations MUST ignore entries of unknown type. 1836 5.3.2. source 1838 Type: "String" (optional) 1840 The source from which updated versions of this group may be retrieved 1841 from. The value MUST be a URI. 1843 6. JSCalendar object examples 1845 The following examples illustrate several aspects of the JSCalendar 1846 data model and format. The examples may omit mandatory or additional 1847 properties, which is indicated by a placeholder property with key 1848 "...". While most of the examples use calendar event objects, they 1849 are also illustrative for tasks. 1851 6.1. Simple event 1853 This example illustrates a simple one-time event. It specifies a 1854 one-time event that begins on January 15, 2018 at 1pm New York local 1855 time and ends after 1 hour. 1857 { 1858 "@type": "jsevent", 1859 "uid": "2a358cee-6489-4f14-a57f-c104db4dc2f1", 1860 "updated": "2018-01-15T18:00:00Z", 1861 "title": "Some event", 1862 "start": "2018-01-15T13:00:00", 1863 "timeZone": "America/New_York", 1864 "duration": "PT1H" 1865 } 1867 6.2. Simple task 1869 This example illustrates a simple task for a plain to-do item. 1871 { 1872 "@type": "jstask", 1873 "uid": "2a358cee-6489-4f14-a57f-c104db4dc2f2", 1874 "updated": "2018-01-15T18:00:00Z", 1875 "title": "Do something" 1876 } 1878 6.3. Simple group 1880 This example illustrates a simple calendar object group that contains 1881 an event and a task. 1883 { 1884 "@type": "jsgroup", 1885 "uid": "2a358cee-6489-4f14-a57f-c104db4dc343", 1886 "updated": "2018-01-15T18:00:00Z", 1887 "name": "A simple group", 1888 "entries": [ 1889 { 1890 "@type": "jsevent", 1891 "uid": "2a358cee-6489-4f14-a57f-c104db4dc2f1", 1892 "updated": "2018-01-15T18:00:00Z", 1893 "title": "Some event", 1894 "start": "2018-01-15T13:00:00", 1895 "timeZone": "America/New_York", 1896 "duration": "PT1H" 1897 }, 1898 { 1899 "@type": "jstask", 1900 "uid": "2a358cee-6489-4f14-a57f-c104db4dc2f2", 1901 "updated": "2018-01-15T18:00:00Z", 1902 "title": "Do something" 1903 } 1904 ] 1905 } 1907 6.4. All-day event 1909 This example illustrates an event for an international holiday. It 1910 specifies an all-day event on April 1 that occurs every year since 1911 the year 1900. 1913 { 1914 "...": "", 1915 "title": "April Fool's Day", 1916 "isAllDay": true, 1917 "start": "1900-04-01T00:00:00", 1918 "duration": "P1D", 1919 "recurrenceRule": { 1920 "frequency": "yearly" 1921 } 1922 } 1924 6.5. Task with a due date 1926 This example illustrates a task with a due date. It is a reminder to 1927 buy groceries before 6pm Vienna local time on January 19, 2018. The 1928 calendar user expects to need 1 hour for shopping. 1930 { 1931 "...": "", 1932 "title": "Buy groceries", 1933 "due": "2018-01-19T18:00:00", 1934 "timeZone": "Europe/Vienna", 1935 "estimatedDuration": "PT1H" 1936 } 1938 6.6. Event with end time-zone 1940 This example illustrates the use of end time-zones by use of an 1941 international flight. The flight starts on April 1, 2018 at 9am in 1942 Berlin local time. The duration of the flight is scheduled at 10 1943 hours 30 minutes. The time at the flights destination is in the same 1944 time-zone as Tokyo. Calendar clients could use the end time-zone to 1945 display the arrival time in Tokyo local time and highlight the time- 1946 zone difference of the flight. The location names can serve as input 1947 for navigation systems. 1949 { 1950 "...": "", 1951 "title": "Flight XY51 to Tokyo", 1952 "start": "2018-04-01T09:00:00", 1953 "timeZone": "Europe/Berlin", 1954 "duration": "PT10H30M", 1955 "locations": { 1956 "2a358cee-6489-4f14-a57f-c104db4dc2f1": { 1957 "rel": "start", 1958 "name": "Frankfurt Airport (FRA)" 1959 }, 1960 "c2c7ac67-dc13-411e-a7d4-0780fb61fb08": { 1961 "rel": "end", 1962 "name": "Narita International Airport (NRT)", 1963 "timeZone": "Asia/Tokyo" 1964 } 1965 } 1966 } 1968 6.7. Floating-time event (with recurrence) 1970 This example illustrates the use of floating-time. Since January 1, 1971 2018, a calendar user blocks 30 minutes every day to practice Yoga at 1972 7am local time, in whatever time-zone the user is located on that 1973 date. 1975 { 1976 "...": "", 1977 "title": "Yoga", 1978 "start": "2018-01-01T07:00:00", 1979 "duration": "PT30M", 1980 "recurrenceRule": { 1981 "frequency": "daily" 1982 } 1983 } 1985 6.8. Event with multiple locations and localization 1987 This example illustrates an event that happens at both a physical and 1988 a virtual location. Fans can see a live convert on premises or 1989 online. The event title and descriptions are localized. 1991 { 1992 "...": "", 1993 "title": "Live from Music Bowl: The Band", 1994 "description": "Go see the biggest music event ever!", 1995 "locale": "en", 1996 "start": "2018-07-04T17:00:00", 1997 "timeZone": "America/New_York", 1998 "duration": "PT3H", 1999 "locations": { 2000 "c0503d30-8c50-4372-87b5-7657e8e0fedd": { 2001 "name": "The Music Bowl", 2002 "description": "Music Bowl, Central Park, New York", 2003 "coordinates": "geo:40.7829,73.9654" 2004 } 2005 }, 2006 "virtualLocations": { 2007 "6f3696c6-1e07-47d0-9ce1-f50014b0041a": { 2008 "name": "Free live Stream from Music Bowl", 2009 "uri": "https://stream.example.com/the_band_2018" 2010 } 2011 }, 2012 "localizations": { 2013 "de": { 2014 "title": "Live von der Music Bowl: The Band!", 2015 "description": "Schau dir das groesste Musikereignis an!", 2016 "virtualLocations/6f3696c6-1e07-47d0-9ce1-f50014b0041a/name": 2017 "Gratis Live-Stream aus der Music Bowl" 2018 } 2019 } 2020 } 2022 6.9. Recurring event with overrides 2024 This example illustrates the use of recurrence overrides. A math 2025 course at a University is held for the first time on January 8, 2018 2026 at 9am London time and occurs every week until June 25, 2018. Each 2027 lecture lasts for one hour and 30 minutes and is located at the 2028 Mathematics department. This event has exceptional occurrences: at 2029 the last occurrence of the course is an exam, which lasts for 2 hours 2030 and starts at 10am. Also, the location of the exam differs from the 2031 usual location. On April 2 no course is held. On January 5 at 2pm 2032 is an optional introduction course, that occurs before the first 2033 regular lecture. 2035 { 2036 "...": "", 2037 "title": "Calculus I", 2038 "start": "2018-01-08T09:00:00", 2039 "timeZone": "Europe/London", 2040 "duration": "PT1H30M", 2041 "locations": { 2042 "2a358cee-6489-4f14-a57f-c104db4dc2f1": { 2043 "title": "Math lab room 1", 2044 "description": "Math Lab I, Department of Mathematics" 2045 } 2046 }, 2047 "recurrenceRule": { 2048 "frequency": "weekly", 2049 "until": "2018-06-25T09:00:00" 2050 }, 2051 "recurrenceOverrides": { 2052 "2018-01-05T14:00:00": { 2053 "title": "Introduction to Calculus I (optional)" 2054 }, 2055 "2018-04-02T09:00:00": { 2056 "excluded": "true" 2057 }, 2058 "2018-06-25T09:00:00": { 2059 "title": "Calculus I Exam", 2060 "start": "2018-06-25T10:00:00", 2061 "duration": "PT2H", 2062 "locations": { 2063 "2a358cee-6489-4f14-a57f-c104db4dc2f1": { 2064 "title": "Big Auditorium", 2065 "description": "Big Auditorium, Other Road" 2066 } 2067 } 2068 } 2069 } 2070 } 2072 6.10. Recurring event with participants 2074 This example illustrates scheduled events. A team meeting occurs 2075 every week since January 8, 2018 at 9am Johannesburg time. The event 2076 owner also chairs the event. Participants meet in a virtual meeting 2077 room. An attendee has accepted the invitation, but on March 8, 2018 2078 he is unavailable and declined participation for this occurrence. 2080 { 2081 "...": "", 2082 "title": "FooBar team meeting", 2083 "start": "2018-01-08T09:00:00", 2084 "timeZone": "Africa/Johannesburg", 2085 "duration": "PT1H", 2086 "virtualLocations": { 2087 "2a358cee-6489-4f14-a57f-c104db4dc2f1": { 2088 "name": "ChatMe meeting room", 2089 "uri": "https://chatme.example.com?id=1234567" 2090 } 2091 }, 2092 "recurrenceRule": { 2093 "frequency": "weekly" 2094 }, 2095 "replyTo": { 2096 "imip": "mailto:6489-4f14-a57f-c1@schedule.example.com" 2097 }, 2098 "participants": { 2099 "dG9tQGZvb2Jhci5leGFtcGxlLmNvbQ": { 2100 "name": "Tom Tool", 2101 "email": "tom@foobar.example.com", 2102 "sendTo": { 2103 "imip": "mailto:6489-4f14-a57f-c1@calendar.example.com" 2104 }, 2105 "participationStatus": "accepted", 2106 "roles": { 2107 "attendee": true 2108 } 2109 }, 2110 "em9lQGZvb2Jhci5leGFtcGxlLmNvbQ": { 2111 "name": "Zoe Zelda", 2112 "email": "zoe@foobar.example.com", 2113 "sendTo": { 2114 "imip": "mailto:zoe@foobar.example.com" 2115 }, 2116 "participationStatus": "accepted", 2117 "roles": { 2118 "owner": true, 2119 "attendee": true, 2120 "chair": true 2121 } 2122 }, 2123 "...": "" 2124 }, 2125 "recurrenceOverrides": { 2126 "2018-03-08T09:00:00": { 2127 "participants/dG9tQGZvb2Jhci5leGFtcGxlLmNvbQ/participationStatus": 2128 "declined" 2129 } 2130 } 2132 } 2134 7. Security Considerations 2136 The use of JSON as a format does have its own inherent security risks 2137 as discussed in Section 12 of [RFC8259]. Even though JSON is 2138 considered a safe subset of JavaScript, it should be kept in mind 2139 that a flaw in the parser processing JSON could still impose a 2140 threat, which doesn't arise with conventional iCalendar data. 2142 With this in mind, a parser for JSON data aware of the security 2143 implications should be used for the format described in this 2144 document. For example, the use of JavaScript's "eval()" function is 2145 considered an unacceptable security risk, as described in Section 12 2146 of[RFC8259]. A native parser with full awareness of the JSON format 2147 should be preferred. 2149 8. IANA Considerations 2151 This document defines a MIME media type for use with JSCalendar data 2152 formatted in JSON. 2154 Type name: application 2156 Subtype name: jscalendar+json 2158 Required parameters: type 2160 The "type" parameter conveys the type of the JSCalendar data in 2161 the body part, with the value being one of "jsevent", "jstask", or 2162 "jsgroup". The parameter MUST NOT occur more than once. It MUST 2163 match the value of the "@type" property of the JSON-formatted 2164 JSCalendar object in the body. 2166 Optional parameters: none 2168 Encoding considerations: Same as encoding considerations of 2169 application/json as specified in RFC8529, Section 11 [RFC8259]. 2171 Security considerations: See Section 7 of this document. 2173 Interoperability considerations: This media type provides an 2174 alternative to iCalendar, jCal and proprietary JSON-based 2175 calendaring data formats. 2177 Published specification: This specification. 2179 Applications that use this media type: Applications that currently 2180 make use of the text/calendar and application/calendar+json media 2181 types can use this as an alternative. Similarily, applications 2182 that use the application/json media type to transfer calendaring 2183 data can use this to further specify the content. 2185 Fragment identifier considerations: N/A 2187 Additional information: 2189 Magic number(s): N/A 2191 File extensions(s): N/A 2193 Macintosh file type code(s): N/A 2195 Person & email address to contact for further 2196 information: 2197 calext@ietf.org 2199 Intended usage: COMMON 2201 Restrictions on usage: N/A 2203 Author: See the "Author's Address" section of this document. 2205 Change controller: IETF 2207 9. Acknowledgments 2209 The authors would like to thank the members of CalConnect for their 2210 valuable contributions. This specification originated from the work 2211 of the API technical committee of CalConnect, the Calendaring and 2212 Scheduling Consortium. 2214 10. References 2216 10.1. Normative References 2218 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 2219 Requirement Levels", BCP 14, RFC 2119, 2220 DOI 10.17487/RFC2119, March 1997, 2221 . 2223 [RFC2392] Levinson, E., "Content-ID and Message-ID Uniform Resource 2224 Locators", RFC 2392, DOI 10.17487/RFC2392, August 1998, 2225 . 2227 [RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet: 2228 Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002, 2229 . 2231 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 2232 Resource Identifier (URI): Generic Syntax", STD 66, 2233 RFC 3986, DOI 10.17487/RFC3986, January 2005, 2234 . 2236 [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally 2237 Unique IDentifier (UUID) URN Namespace", RFC 4122, 2238 DOI 10.17487/RFC4122, July 2005, 2239 . 2241 [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data 2242 Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006, 2243 . 2245 [RFC4791] Daboo, C., Desruisseaux, B., and L. Dusseault, 2246 "Calendaring Extensions to WebDAV (CalDAV)", RFC 4791, 2247 DOI 10.17487/RFC4791, March 2007, 2248 . 2250 [RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and 2251 Scheduling Core Object Specification (iCalendar)", 2252 RFC 5545, DOI 10.17487/RFC5545, September 2009, 2253 . 2255 [RFC5546] Daboo, C., Ed., "iCalendar Transport-Independent 2256 Interoperability Protocol (iTIP)", RFC 5546, 2257 DOI 10.17487/RFC5546, December 2009, 2258 . 2260 [RFC5646] Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying 2261 Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646, 2262 September 2009, . 2264 [RFC5870] Mayrhofer, A. and C. Spanring, "A Uniform Resource 2265 Identifier for Geographic Locations ('geo' URI)", 2266 RFC 5870, DOI 10.17487/RFC5870, June 2010, 2267 . 2269 [RFC6047] Melnikov, A., Ed., "iCalendar Message-Based 2270 Interoperability Protocol (iMIP)", RFC 6047, 2271 DOI 10.17487/RFC6047, December 2010, 2272 . 2274 [RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type 2275 Specifications and Registration Procedures", BCP 13, 2276 RFC 6838, DOI 10.17487/RFC6838, January 2013, 2277 . 2279 [RFC6901] Bryan, P., Ed., Zyp, K., and M. Nottingham, Ed., 2280 "JavaScript Object Notation (JSON) Pointer", RFC 6901, 2281 DOI 10.17487/RFC6901, April 2013, 2282 . 2284 [RFC7265] Kewisch, P., Daboo, C., and M. Douglass, "jCal: The JSON 2285 Format for iCalendar", RFC 7265, DOI 10.17487/RFC7265, May 2286 2014, . 2288 [RFC7493] Bray, T., Ed., "The I-JSON Message Format", RFC 7493, 2289 DOI 10.17487/RFC7493, March 2015, 2290 . 2292 [RFC7529] Daboo, C. and G. Yakushev, "Non-Gregorian Recurrence Rules 2293 in the Internet Calendaring and Scheduling Core Object 2294 Specification (iCalendar)", RFC 7529, 2295 DOI 10.17487/RFC7529, May 2015, 2296 . 2298 [RFC7808] Douglass, M. and C. Daboo, "Time Zone Data Distribution 2299 Service", RFC 7808, DOI 10.17487/RFC7808, March 2016, 2300 . 2302 [RFC7986] Daboo, C., "New Properties for iCalendar", RFC 7986, 2303 DOI 10.17487/RFC7986, October 2016, 2304 . 2306 [RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data 2307 Interchange Format", STD 90, RFC 8259, 2308 DOI 10.17487/RFC8259, December 2017, 2309 . 2311 [RFC8288] Nottingham, M., "Web Linking", RFC 8288, 2312 DOI 10.17487/RFC8288, October 2017, 2313 . 2315 10.2. Informative References 2317 [draft-apthorp-ical-tasks] 2318 "Task Extensions to iCalendar", 2319 . 2321 [draft-ietf-calext-ical-relations] 2322 "Support for iCalendar Relationships", 2323 . 2326 [MIME] "IANA Media Types", . 2329 10.3. URIs 2331 [1] https://www.iana.org/time-zones 2333 [2] https://www.iana.org/assignments/link-relations/link- 2334 relations.xhtml 2336 [3] https://www.w3.org/TR/2011/REC-css3-color-20110607/#svg-color 2338 Authors' Addresses 2340 Neil Jenkins 2341 FastMail 2342 PO Box 234 2343 Collins St West 2344 Melbourne VIC 8007 2345 Australia 2347 Email: neilj@fastmailteam.com 2348 URI: https://www.fastmail.com 2350 Robert Stepanek 2351 FastMail 2352 PO Box 234 2353 Collins St West 2354 Melbourne VIC 8007 2355 Australia 2357 Email: rsto@fastmailteam.com 2358 URI: https://www.fastmail.com