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'CLDR' -- Possible downref: Non-RFC (?) normative reference: ref. 'COLORS' -- Possible downref: Non-RFC (?) normative reference: ref. 'TZDB' Summary: 0 errors (**), 0 flaws (~~), 11 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: August 23, 2020 February 20, 2020 7 JSCalendar: A JSON representation of calendar data 8 draft-ietf-calext-jscalendar-24 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 and, over time, successor to the widely deployed iCalendar data 16 format, and to be unambiguous, extendable, and simple to process. In 17 contrast to the jCal format, which is also JSON-based, JSCalendar is 18 not a direct mapping from iCalendar, but defines the data model 19 independently and expands semantics where appropriate. 21 Status of This Memo 23 This Internet-Draft is submitted in full conformance with the 24 provisions of BCP 78 and BCP 79. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF). Note that other groups may also distribute 28 working documents as Internet-Drafts. The list of current Internet- 29 Drafts is at https://datatracker.ietf.org/drafts/current/. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 This Internet-Draft will expire on August 23, 2020. 38 Copyright Notice 40 Copyright (c) 2020 IETF Trust and the persons identified as the 41 document authors. All rights reserved. 43 This document is subject to BCP 78 and the IETF Trust's Legal 44 Provisions Relating to IETF Documents 45 (https://trustee.ietf.org/license-info) in effect on the date of 46 publication of this document. Please review these documents 47 carefully, as they describe your rights and restrictions with respect 48 to this document. Code Components extracted from this document must 49 include Simplified BSD License text as described in Section 4.e of 50 the Trust Legal Provisions and are provided without warranty as 51 described in the Simplified BSD License. 53 Table of Contents 55 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 56 1.1. Motivation and Relation to iCalendar and jCal . . . . . . 5 57 1.2. Notational Conventions . . . . . . . . . . . . . . . . . 6 58 1.3. Type Signatures . . . . . . . . . . . . . . . . . . . . . 6 59 1.4. Data Types . . . . . . . . . . . . . . . . . . . . . . . 7 60 1.4.1. Int . . . . . . . . . . . . . . . . . . . . . . . . . 7 61 1.4.2. UnsignedInt . . . . . . . . . . . . . . . . . . . . . 7 62 1.4.3. UTCDateTime . . . . . . . . . . . . . . . . . . . . . 7 63 1.4.4. LocalDateTime . . . . . . . . . . . . . . . . . . . . 7 64 1.4.5. Duration . . . . . . . . . . . . . . . . . . . . . . 7 65 1.4.6. SignedDuration . . . . . . . . . . . . . . . . . . . 8 66 1.4.7. Id . . . . . . . . . . . . . . . . . . . . . . . . . 8 67 1.4.8. PatchObject . . . . . . . . . . . . . . . . . . . . . 9 68 1.4.9. Time Zones . . . . . . . . . . . . . . . . . . . . . 9 69 1.4.10. Relation . . . . . . . . . . . . . . . . . . . . . . 9 70 2. JSCalendar Objects . . . . . . . . . . . . . . . . . . . . . 10 71 2.1. JSEvent . . . . . . . . . . . . . . . . . . . . . . . . . 10 72 2.2. JSTask . . . . . . . . . . . . . . . . . . . . . . . . . 11 73 2.3. JSGroup . . . . . . . . . . . . . . . . . . . . . . . . . 11 74 3. Structure of JSCalendar Objects . . . . . . . . . . . . . . . 11 75 3.1. Normalization and Equivalence . . . . . . . . . . . . . . 11 76 3.2. Vendor-specific Property Extensions and Values . . . . . 12 77 4. Common JSCalendar Properties . . . . . . . . . . . . . . . . 12 78 4.1. Metadata Properties . . . . . . . . . . . . . . . . . . . 12 79 4.1.1. @type . . . . . . . . . . . . . . . . . . . . . . . . 12 80 4.1.2. uid . . . . . . . . . . . . . . . . . . . . . . . . . 13 81 4.1.3. relatedTo . . . . . . . . . . . . . . . . . . . . . . 13 82 4.1.4. prodId . . . . . . . . . . . . . . . . . . . . . . . 13 83 4.1.5. created . . . . . . . . . . . . . . . . . . . . . . . 14 84 4.1.6. updated . . . . . . . . . . . . . . . . . . . . . . . 14 85 4.1.7. sequence . . . . . . . . . . . . . . . . . . . . . . 14 86 4.1.8. method . . . . . . . . . . . . . . . . . . . . . . . 14 87 4.2. What and Where Properties . . . . . . . . . . . . . . . . 14 88 4.2.1. title . . . . . . . . . . . . . . . . . . . . . . . . 14 89 4.2.2. description . . . . . . . . . . . . . . . . . . . . . 15 90 4.2.3. descriptionContentType . . . . . . . . . . . . . . . 15 91 4.2.4. showWithoutTime . . . . . . . . . . . . . . . . . . . 15 92 4.2.5. locations . . . . . . . . . . . . . . . . . . . . . . 15 93 4.2.6. virtualLocations . . . . . . . . . . . . . . . . . . 17 94 4.2.7. links . . . . . . . . . . . . . . . . . . . . . . . . 17 95 4.2.8. locale . . . . . . . . . . . . . . . . . . . . . . . 19 96 4.2.9. keywords . . . . . . . . . . . . . . . . . . . . . . 19 97 4.2.10. categories . . . . . . . . . . . . . . . . . . . . . 19 98 4.2.11. color . . . . . . . . . . . . . . . . . . . . . . . . 20 99 4.3. Recurrence Properties . . . . . . . . . . . . . . . . . . 20 100 4.3.1. recurrenceId . . . . . . . . . . . . . . . . . . . . 20 101 4.3.2. recurrenceRules . . . . . . . . . . . . . . . . . . . 20 102 4.3.3. recurrenceOverrides . . . . . . . . . . . . . . . . . 28 103 4.3.4. excluded . . . . . . . . . . . . . . . . . . . . . . 30 104 4.4. Sharing and Scheduling Properties . . . . . . . . . . . . 30 105 4.4.1. priority . . . . . . . . . . . . . . . . . . . . . . 30 106 4.4.2. freeBusyStatus . . . . . . . . . . . . . . . . . . . 30 107 4.4.3. privacy . . . . . . . . . . . . . . . . . . . . . . . 30 108 4.4.4. replyTo . . . . . . . . . . . . . . . . . . . . . . . 32 109 4.4.5. participants . . . . . . . . . . . . . . . . . . . . 32 110 4.5. Alerts Properties . . . . . . . . . . . . . . . . . . . . 37 111 4.5.1. useDefaultAlerts . . . . . . . . . . . . . . . . . . 37 112 4.5.2. alerts . . . . . . . . . . . . . . . . . . . . . . . 37 113 4.6. Multilingual Properties . . . . . . . . . . . . . . . . . 39 114 4.6.1. localizations . . . . . . . . . . . . . . . . . . . . 39 115 4.7. Time Zone Properties . . . . . . . . . . . . . . . . . . 40 116 4.7.1. timeZone . . . . . . . . . . . . . . . . . . . . . . 40 117 4.7.2. timeZones . . . . . . . . . . . . . . . . . . . . . . 40 118 5. Type-specific JSCalendar Properties . . . . . . . . . . . . . 43 119 5.1. JSEvent Properties . . . . . . . . . . . . . . . . . . . 43 120 5.1.1. start . . . . . . . . . . . . . . . . . . . . . . . . 43 121 5.1.2. duration . . . . . . . . . . . . . . . . . . . . . . 43 122 5.1.3. status . . . . . . . . . . . . . . . . . . . . . . . 43 123 5.2. JSTask Properties . . . . . . . . . . . . . . . . . . . . 44 124 5.2.1. due . . . . . . . . . . . . . . . . . . . . . . . . . 44 125 5.2.2. start . . . . . . . . . . . . . . . . . . . . . . . . 44 126 5.2.3. estimatedDuration . . . . . . . . . . . . . . . . . . 44 127 5.2.4. progress . . . . . . . . . . . . . . . . . . . . . . 44 128 5.2.5. progressUpdated . . . . . . . . . . . . . . . . . . . 45 129 5.3. JSGroup Properties . . . . . . . . . . . . . . . . . . . 45 130 5.3.1. entries . . . . . . . . . . . . . . . . . . . . . . . 46 131 5.3.2. source . . . . . . . . . . . . . . . . . . . . . . . 46 132 6. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 46 133 6.1. Simple event . . . . . . . . . . . . . . . . . . . . . . 46 134 6.2. Simple task . . . . . . . . . . . . . . . . . . . . . . . 47 135 6.3. Simple group . . . . . . . . . . . . . . . . . . . . . . 47 136 6.4. All-day event . . . . . . . . . . . . . . . . . . . . . . 48 137 6.5. Task with a due date . . . . . . . . . . . . . . . . . . 48 138 6.6. Event with end time-zone . . . . . . . . . . . . . . . . 49 139 6.7. Floating-time event (with recurrence) . . . . . . . . . . 49 140 6.8. Event with multiple locations and localization . . . . . 50 141 6.9. Recurring event with overrides . . . . . . . . . . . . . 51 142 6.10. Recurring event with participants . . . . . . . . . . . . 52 143 7. Security Considerations . . . . . . . . . . . . . . . . . . . 54 144 7.1. Expanding Recurrences . . . . . . . . . . . . . . . . . . 54 145 7.2. JSON Parsing . . . . . . . . . . . . . . . . . . . . . . 54 146 7.3. URI Values . . . . . . . . . . . . . . . . . . . . . . . 55 147 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 55 148 8.1. Media Type Registration . . . . . . . . . . . . . . . . . 55 149 8.2. Creation of "JSCalendar Properties" Registry . . . . . . 56 150 8.2.1. Preliminary Community Review . . . . . . . . . . . . 57 151 8.2.2. Submit Request to IANA . . . . . . . . . . . . . . . 57 152 8.2.3. Designated Expert Review . . . . . . . . . . . . . . 57 153 8.2.4. Change Procedures . . . . . . . . . . . . . . . . . . 58 154 8.2.5. JMAP Properties Registry Template . . . . . . . . . . 58 155 8.2.6. Initial Contents for the JSCalendar Properties 156 Registry . . . . . . . . . . . . . . . . . . . . . . 59 157 8.3. Creation of "JSCalendar Types" Registry . . . . . . . . . 66 158 8.3.1. JMAP Types Registry Template . . . . . . . . . . . . 66 159 8.3.2. Initial Contents for the JSCalendar Types Registry . 66 160 8.4. Creation of "JSCalendar Enum Values" Registry . . . . . . 68 161 8.4.1. JMAP Enum Subregistry Creation Template . . . . . . . 68 162 8.4.2. JMAP Enum Subregistry Template . . . . . . . . . . . 68 163 8.4.3. Initial Contents for the JSCalendar Enum Registry . . 69 164 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 73 165 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 73 166 10.1. Normative References . . . . . . . . . . . . . . . . . . 73 167 10.2. Informative References . . . . . . . . . . . . . . . . . 75 168 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 76 170 1. Introduction 172 This document defines a data model for calendar event and task 173 objects, or groups of such objects, in electronic calendar 174 applications and systems. It aims to be unambiguous, extendable and 175 simple to process. 177 The key design considerations for this data model are as follows: 179 o The attributes of the calendar entry represented must be described 180 as simple key-value pairs. Simple events are simple to represent; 181 complex events can be modelled accurately. 183 o Wherever possible, there should be only one way to express the 184 desired semantics, reducing complexity. 186 o The data model should avoid ambiguities, which often lead to 187 interoperability issues between implementations. 189 o The data model should be compatible with the iCalendar data format 190 [RFC5545] [RFC7986] and extensions, but the specification should 191 add new attributes where the iCalendar format currently lacks 192 expressivity, and drop seldom-used, obsolete, or redundant 193 properties. This means translation with no loss of semantics 194 should be easy with most common iCalendar files. 196 o Extensions, such as new properties and components, generally do 197 not require updates to this document. 199 The representation of this data model is defined in the I-JSON format 200 [RFC7493], which is a strict subset of the JavaScript Object Notation 201 (JSON) Data Interchange Format [RFC8259]. Using JSON is mostly a 202 pragmatic choice: its widespread use makes JSCalendar easier to 203 adopt, and the ready availability of production-ready JSON 204 implementations eliminates a whole category of parser-related 205 interoperability issues, which iCalendar has often suffered from. 207 1.1. Motivation and Relation to iCalendar and jCal 209 The iCalendar data format [RFC5545], a widely deployed interchange 210 format for calendaring and scheduling data, has served calendaring 211 vendors for a long while, but contains some ambiguities and pitfalls 212 that can not be overcome without backward-incompatible changes. 214 Sources of implementation errors include the following: 216 o iCalendar defines various formats for local times, UTC time, and 217 dates. 219 o iCalendar requires custom time zone definitions within a single 220 calendar component. 222 o iCalendar's definition of recurrence rules is ambiguous and has 223 resulted in differing understandings even between experienced 224 calendar developers. 226 o The iCalendar format itself causes interoperability issues due to 227 misuse of CRLF-terminated strings, line continuations, and subtle 228 differences among iCalendar parsers. 230 In recent years, many new products and services have appeared that 231 wish to use a JSON representation of calendar data within their APIs. 232 The JSON format for iCalendar data, jCal [RFC7265], is a direct 233 mapping between iCalendar and JSON. In its effort to represent full 234 iCalendar semantics, it inherits all the same pitfalls and uses a 235 complicated JSON structure unlike most common JSON data 236 representations. 238 As a consequence, since the standardization of jCal, the majority of 239 implementations and service providers either kept using iCalendar, or 240 came up with their own proprietary JSON representations, which are 241 incompatible with each other and often suffer from common pitfalls, 242 such as storing event start times in UTC (which become incorrect if 243 the timezone's rules change in the future). JSCalendar meets the 244 demand for JSON-formatted calendar data that is free of such known 245 problems and provides a standard representation as an alternative to 246 the proprietary formats. 248 1.2. Notational Conventions 250 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 251 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 252 "OPTIONAL" in this document are to be interpreted as described in BCP 253 14 [RFC2119] [RFC8174] when, and only when, they appear in all 254 capitals, as shown here. 256 The underlying format used for this specification is JSON. 257 Consequently, the terms "object" and "array" as well as the four 258 primitive types (strings, numbers, booleans, and null) are to be 259 interpreted as described in Section 1 of [RFC8259]. 261 Some examples in this document contain "partial" JSON documents used 262 for illustrative purposes. In these examples, three periods "..." 263 are used to indicate a portion of the document that has been removed 264 for compactness. 266 1.3. Type Signatures 268 Type signatures are given for all JSON values in this document. The 269 following conventions are used: 271 o "*" - The type is undefined (the value could be any type, although 272 permitted values may be constrained by the context of this value). 274 o "String" - The JSON string type. 276 o "Number" - The JSON number type. 278 o "Boolean" - The JSON boolean type. 280 o "A[B]" - A JSON object where the keys are all of type "A", and the 281 values are all of type "B". 283 o "A[]" - An array of values of type "A". 285 o "A|B" - The value is either of type "A" or of type "B". 287 Other types may also be given, with their representations defined 288 elsewhere in this document. 290 1.4. Data Types 292 In addition to the standard JSON data types, the following data types 293 are used in this specification: 295 1.4.1. Int 297 Where "Int" is given as a data type, it means an integer in the range 298 -2^53+1 <= value <= 2^53-1, the safe range for integers stored in a 299 floating-point double, represented as a JSON "Number". 301 1.4.2. UnsignedInt 303 Where "UnsignedInt" is given as a data type, it means an integer in 304 the range 0 <= value <= 2^53-1, represented as a JSON "Number". 306 1.4.3. UTCDateTime 308 This is a string in [RFC3339] "date-time" format, with the further 309 restrictions that any letters MUST be in uppercase, the time 310 component MUST be included and the time offset MUST be the character 311 "Z". Fractional second values MUST NOT be included unless non-zero 312 and MUST NOT have trailing zeros, to ensure there is only a single 313 representation for each date-time. 315 For example "2010-10-10T10:10:10.003Z" is OK, but 316 "2010-10-10T10:10:10.000Z" is invalid and MUST be encoded as 317 "2010-10-10T10:10:10Z". 319 1.4.4. LocalDateTime 321 This is a date-time string with no time zone/offset information. It 322 is otherwise in the same format as UTCDateTime, including fractional 323 seconds. For example "2006-01-02T15:04:05" and 324 "2006-01-02T15:04:05.003" are both valid. The time zone to associate 325 the LocalDateTime with comes from an associated property, or if no 326 time zone is associated it defines *floating time*. Floating date- 327 times are not tied to any specific time zone. Instead, they occur in 328 each time zone at the given wall-clock time (as opposed to the same 329 instant point in time). 331 1.4.5. Duration 333 Where Duration is given as a type, it means a length of time 334 represented by a subset of ISO8601 duration format, as specified by 335 the following ABNF: 337 dur-secfrac = "." 1*DIGIT 338 dur-second = 1*DIGIT [dur-secfrac] "S" 339 dur-minute = 1*DIGIT "M" [dur-second] 340 dur-hour = 1*DIGIT "H" [dur-minute] 341 dur-time = "T" (dur-hour / dur-minute / dur-second) 342 dur-day = 1*DIGIT "D" 343 dur-week = 1*DIGIT "W" 345 duration = "P" (dur-day [dur-time] / dur-time / dur-week) 347 In addition, the duration MUST NOT include fractional second values 348 unless the fraction is non-zero. 350 1.4.6. SignedDuration 352 A SignedDuration represents a length of time that may be positive or 353 negative and is typically used to express the offset of a point in 354 time relative to an associated time. It is represented as a 355 Duration, optionally preceded by a sign character. It is specified 356 by the following ABNF: 358 signed-duration = ["+" / "-"] duration 360 A negative sign indicates a point in time at or before the associated 361 time, a positive or no sign a time at or after the associated time. 363 1.4.7. Id 365 Where "Id" is given as a data type, it means a "String" of at least 1 366 and a maximum of 255 octets in size, and it MUST only contain 367 characters from the "URL and Filename Safe" base64url alphabet, as 368 defined in Section 5 of [RFC4648], excluding the pad character ("="). 369 This means the allowed characters are the ASCII alphanumeric 370 characters ("A-Za-z0-9"), hyphen ("-"), and underscore ("_"). 372 Unless otherwise specified, Ids are arbitrary and only have meaning 373 within the object where they are being used. Ids need not be unique 374 among different objects. For example, two JSEvent objects might use 375 the same ids in their respective "links" properties. Or within the 376 same JSEvent object the same Id could appear in the "participants" 377 and "alerts" properties. These situations do not imply any semantic 378 connections among the objects. 380 Nevertheless, a UUID is typically a good choice. 382 1.4.8. PatchObject 384 A PatchObject is of type "String[*]", and represents an unordered set 385 of patches on a JSON object. Each key is a path represented in a 386 subset of JSON pointer format [RFC6901]. The paths have an implicit 387 leading "/", so each key is prefixed with "/" before applying the 388 JSON pointer evaluation algorithm. 390 A patch within a PatchObject is only valid if all of the following 391 conditions apply: 393 1. The pointer MUST NOT insert/delete from an array; the array MUST 394 be replaced in its entirety instead. 396 2. When evaluating a path, all parts prior to the last (i.e., the 397 value after the final slash) MUST exist. 399 3. There MUST NOT be two patches in the PatchObject where the 400 pointer of one is a prefix of the pointer of the other, e.g., 401 "alerts/foo/offset" and "alerts". 403 The value associated with each pointer is either: 405 o null: Remove the property at the given path from the patched 406 object. If the property is not present in the object, this a no- 407 op. 409 o Anything else: Set the value for the property to this value (this 410 may be a replacement or addition to the object being patched). 412 Implementations MUST reject in its entirety a PatchObject if any of 413 its patches is invalid. Implementations MUST NOT apply partial 414 patches. 416 1.4.9. Time Zones 418 By default, time zones in JSCalendar are identified by their names in 419 the IANA Time Zone Database [TZDB], and the zone rules of the 420 respective zone records apply. 422 Implementations MAY embed the definitions of custom time zones in the 423 "timeZones" property (see Section 4.7.2). 425 1.4.10. Relation 427 A Relation object defines the relation to other objects, using a 428 possibly empty set of relation types. The object that defines this 429 relation is the linking object, while the other object is the linked 430 object. The Relation object has the following properties: 432 o @type: "String" (mandatory) 434 Specifies the type of this object. This MUST be "Relation". 436 o relation: "String[Boolean]" (optional, default: empty Object) 438 Describes how the linked object is related to the linking object. 439 The relation is defined as a set of relation types. If empty, the 440 relationship between the two objects is unspecified. 442 Keys in the set MUST be one of the following values, or specified 443 in the property definition where the Relation object is used, or a 444 value registered in the IANA JSCalendar Enum Registry, or a 445 vendor-specific value: 447 * "first": The linked object is the first in a series the linking 448 object is part of. 450 * "next": The linked object is the next in a series the linking 451 object is part of. 453 * "child": The linked object is a subpart of the linking object. 455 * "parent": The linking object is a subpart of the linked object. 457 The value for each key in the set MUST be true. 459 2. JSCalendar Objects 461 This section describes the calendar object types specified by 462 JSCalendar. 464 2.1. JSEvent 466 Media type: "application/jscalendar+json;type=jsevent" 468 A JSEvent represents a scheduled amount of time on a calendar, 469 typically a meeting, appointment, reminder or anniversary. It is 470 required to start at a certain point in time and typically has a non- 471 zero duration. Multiple participants may partake in the event at 472 multiple locations. 474 The @type (Section 4.1.1) property value MUST be "jsevent". 476 2.2. JSTask 478 Media type: "application/jscalendar+json;type=jstask" 480 A JSTask represents an action-item, assignment, to-do or work item. 481 It may start and be due at certain points in time, may take some 482 estimated time to complete, and may recur, none of which is required. 484 The @type (Section 4.1.1) property value MUST be "jstask". 486 2.3. JSGroup 488 Media type: "application/jscalendar+json;type=jsgroup" 490 A JSGroup is a collection of JSEvent (Section 2.1) and/or JSTask 491 (Section 2.2) objects. Typically, objects are grouped by topic 492 (e.g., by keywords) or calendar membership. 494 The @type (Section 4.1.1) property value MUST be "jsgroup". 496 3. Structure of JSCalendar Objects 498 A JSCalendar object is a JSON object, which MUST be valid I-JSON (a 499 stricter subset of JSON), as specified in [RFC8259]. Property names 500 and values are case-sensitive. 502 The object has a collection of properties, as specified in the 503 following sections. Properties are specified as being either 504 mandatory or optional. Optional properties may have a default value, 505 if explicitly specified in the property definition. 507 3.1. Normalization and Equivalence 509 JSCalendar aims to provide unambiguous definitions for value types 510 and properties, but does not define a general normalization or 511 equivalence method for JSCalendar objects and types. This is because 512 the notion of equivalence might range from byte-level equivalence to 513 semantic equivalence, depending on the respective use case (for 514 example, the CalDAV protocol [RFC4791] requires octet equivalence of 515 the encoded calendar object to determine ETag equivalence). 517 Normalization of JSCalendar objects is hindered because of the 518 following reasons: 520 o Custom JSCalendar properties may contain arbitrary JSON values, 521 including arrays. However, equivalence of arrays might or might 522 not depend on the order of elements, depending on the respective 523 property definition. 525 o Several JSCalendar property values are defined as URIs and media 526 types, but normalization of these types is inherently protocol- 527 and scheme-specific, depending on the use-case of the equivalence 528 definition (see Section 6 of [RFC3986]). 530 Considering this, the definition of equivalence and normalization is 531 left to client and server implementations and to be negotiated by a 532 calendar exchange protocol or defined elsewhere. 534 3.2. Vendor-specific Property Extensions and Values 536 Vendors MAY add additional properties to the calendar object to 537 support their custom features. The names of these properties MUST be 538 prefixed with a domain name controlled by the vendor to avoid 539 conflict, e.g., "example.com/customprop". 541 Some JSCalendar properties allow vendor-specific value extensions. 542 Such vendor-specific values MUST be prefixed with a domain name 543 controlled by the vendor, e.g., "example.com/customrel". 545 Vendors are strongly encouraged to register any new property values 546 or extensions that are useful to other systems as well, rather than 547 use a vendor-specific prefix. 549 4. Common JSCalendar Properties 551 This section describes the properties that are common to the various 552 JSCalendar object types. Specific JSCalendar object types may only 553 support a subset of these properties. The object type definitions in 554 Section 5 describe the set of supported properties per type. 556 4.1. Metadata Properties 558 4.1.1. @type 560 Type: "String" (mandatory). 562 Specifies the type which this object represents. This MUST be one of 563 the following values: 565 o "jsevent": a JSCalendar event (Section 2.1). 567 o "jstask": a JSCalendar task (Section 2.2). 569 o "jsgroup": a JSCalendar group (Section 2.3). 571 4.1.2. uid 573 Type: "String" (mandatory). 575 A globally unique identifier, used to associate the object as the 576 same across different systems, calendars and views. The value of 577 this property MUST be unique across all JSCalendar objects, even if 578 they are of different type. [RFC4122] describes a range of 579 established algorithms to generate universally unique identifiers 580 (UUID). UUID version 4, described in Section 4.4 of [RFC4122], is 581 RECOMMENDED. 583 For compatibility with [RFC5545] UIDs, implementations MUST be able 584 to receive and persist values of at least 255 octets for this 585 property, but they MUST NOT truncate values in the middle of a UTF-8 586 multi-octet sequence. 588 4.1.3. relatedTo 590 Type: "String[Relation]" (optional). 592 Relates the object to other JSCalendar objects. This is represented 593 as a map of the UIDs of the related objects to information about the 594 relation. 596 If an object is split to make a "this and future" change to a 597 recurrence, the original object MUST be truncated to end at the 598 previous occurrence before this split, and a new object created to 599 represent all the occurrences after the split. A "next" relation 600 MUST be set on the original object's relatedTo property for the UID 601 of the new object. A "first" relation for the UID of the first 602 object in the series MUST be set on the new object. Clients can then 603 follow these UIDs to get the complete set of objects if the user 604 wishes to modify them all at once. 606 4.1.4. prodId 608 Type: "String" (optional). 610 The identifier for the product that last updated the JSCalendar 611 object. This should be set whenever the data in the object is 612 modified (i.e., whenever the "updated" property is set). 614 The vendor of the implementation SHOULD ensure that this is a 615 globally unique identifier, using some technique such as an FPI 616 value, as defined in [ISO.9070.1991]. It MUST only use characters of 617 an iCalendar TEXT data value (see Section 3.3.11 of [RFC5545]). 619 This property SHOULD NOT be used to alter the interpretation of a 620 JSCalendar object beyond the semantics specified in this document. 621 For example, it is not to be used to further the understanding of 622 non-standard properties, a practice that is knows to cause long-term 623 interoperability problems. 625 4.1.5. created 627 Type: "UTCDateTime" (optional). 629 The date and time this object was initially created. 631 4.1.6. updated 633 Type: "UTCDateTime" (mandatory). 635 The date and time the data in this object was last modified (or its 636 creation date/time if not modified since). 638 4.1.7. sequence 640 Type: "UnsignedInt" (optional, default: 0). 642 Initially zero, this MUST be incremented by one every time a change 643 is made to the object, except if the change only modifies the 644 "participants" property (see Section 4.4.5). 646 This is used as part of iTIP [RFC5546] to know which version of the 647 object a scheduling message relates to. 649 4.1.8. method 651 Type: "String" (optional). 653 The iTIP [RFC5546] method, in lowercase. This MUST only be present 654 if the JSCalendar object represents an iTIP scheduling message. 656 4.2. What and Where Properties 658 4.2.1. title 660 Type: "String" (optional, default: empty String). 662 A short summary of the object. 664 4.2.2. description 666 Type: "String" (optional, default: empty String). 668 A longer-form text description of the object. The content is 669 formatted according to the "descriptionContentType" property. 671 4.2.3. descriptionContentType 673 Type: "String" (optional, default: "text/plain"). 675 Describes the media type [RFC6838] of the contents of the 676 "description" property. Media types MUST be sub-types of type 677 "text", and SHOULD be "text/plain" or "text/html" [MIME]. They MAY 678 include parameters and the "charset" parameter value MUST be "utf-8", 679 if specified. Descriptions of type "text/html" MAY contain "cid" 680 URLs [RFC2392] to reference links in the calendar object by use of 681 the "cid" property of the Link object. 683 4.2.4. showWithoutTime 685 Type: "Boolean" (optional, default: false). 687 Indicates that the time is not important to display to the user when 688 rendering this calendar object. An example of this is an event that 689 conceptually occurs all day or across multiple days, such as "New 690 Year's Day" or "Italy Vacation". While the time component is 691 important for free-busy calculations and checking for scheduling 692 clashes, calendars may choose to omit displaying it and/or display 693 the object separately to other objects to enhance the user's view of 694 their schedule. 696 Such events are also commonly known as "all-day" events. 698 4.2.5. locations 700 Type: "Id[Location]" (optional). 702 A map of location ids to Location objects, representing locations 703 associated with the object. 705 A Location object has the following properties. It MUST have at 706 least one property other than the "relativeTo" property. 708 o @type: "String" (mandatory) 710 Specifies the type of this object. This MUST be "Location". 712 o name: "String" (optional) 714 The human-readable name of the location. 716 o description: "String" (optional) 718 Human-readable, plain-text instructions for accessing this 719 location. This may be an address, set of directions, door access 720 code, etc. 722 o locationTypes: "String[Boolean]" (optional) 724 A set of one or more location types that describe this location. 725 All types MUST be from the Location Types Registry as defined in 726 [RFC4589]. The set is represented as a map, with the keys being 727 the location types. The value for each key in the map MUST be 728 true. 730 o relativeTo: "String" (optional) 732 Specifies the relation between this location and the time of the 733 JSCalendar object. This is primarily to allow events representing 734 travel to specify the location of departure (at the start of the 735 event) and location of arrival (at the end); this is particularly 736 important if these locations are in different time zones, as a 737 client may wish to highlight this information for the user. 739 This MUST be one of the following values, a value registered in 740 the IANA JSCalendar Enum Registry, or a vendor-specific value. 741 Any value the client or server doesn't understand should be 742 treated the same as if this property is omitted. 744 * "start": The event/task described by this JSCalendar object 745 occurs at this location at the time the event/task starts. 747 * "end": The event/task described by this JSCalendar object 748 occurs at this location at the time the event/task ends. 750 o timeZone: "String" (optional) 752 A time zone for this location. See also Section 1.4.9. 754 o coordinates: "String" (optional) 756 A "geo:" URI [RFC5870] for the location. 758 o linkIds: "Id[Boolean]" (optional) 759 A set of link ids for links to alternative representations of this 760 location. Each key in the set MUST be the id of a Link object 761 defined in the "links" property of this calendar object. The 762 value for each key in the set MUST be true. If there are no 763 links, this MUST be omitted (rather than specified as an empty 764 set). 766 For example, an alternative representation could be in vCard 767 format. 769 4.2.6. virtualLocations 771 Type: "Id[VirtualLocation]" (optional). 773 A map of ids to VirtualLocation objects, representing virtual 774 locations, such as video conferences or chat rooms, associated with 775 the object. 777 A VirtualLocation object has the following properties. 779 o @type: "String" (mandatory) 781 Specifies the type of this object. This MUST be 782 "VirtualLocation". 784 o name: "String" (optional, default: empty String) 786 The human-readable name of the virtual location. 788 o description: "String" (optional) 790 Human-readable plain-text instructions for accessing this 791 location. This may be an address, set of directions, door access 792 code, etc. 794 o uri: "String" (mandatory) 796 A URI that represents how to connect to this virtual location. 798 This may be a telephone number (represented using the "tel:" 799 scheme, e.g., "tel:+1-555-555-555") for a teleconference, a web 800 address for online chat, or any custom URI. 802 4.2.7. links 804 Type: "Id[Link]" (optional). 806 A map of link ids to Link objects, representing external resources 807 associated with the object. 809 A Link object has the following properties: 811 o @type: "String" (mandatory) 813 Specifies the type of this object. This MUST be "Link". 815 o href: "String" (mandatory) 817 A URI from which the resource may be fetched. 819 This MAY be a "data:" URL [RFC2397], but it is recommended that 820 the file be hosted on a server to avoid embedding arbitrarily 821 large data in JSCalendar object instances. 823 o cid: "String" (optional) 825 This MUST be a valid "content-id" value according to the 826 definition of Section 2 in [RFC2392]. The value MUST be unique 827 within this Link object but has no meaning beyond that. It MAY be 828 different from the link id for this Link object. 830 o contentType: "String" (optional) 832 The media type [RFC6838] of the resource, if known. 834 o size: "UnsignedInt" (optional) 836 The size, in octets, of the resource when fully decoded (i.e., the 837 number of octets in the file the user would download), if known. 839 o rel: "String" (optional) 841 Identifies the relation of the linked resource to the object. If 842 set, the value MUST be a relation type from the IANA registry 843 [LINKRELS], as established in [RFC8288]. 845 Links with a rel of "enclosure" SHOULD be considered by the client 846 as attachments for download. 848 Links with a rel of "describedby" SHOULD be considered by the 849 client to be an alternative representation of the description. 851 Links with a rel of "icon" SHOULD be considered by the client to 852 be an image that it may use when presenting the calendar data to a 853 user. The "display" property may be set to indicate the purpose 854 of this image. 856 o display: "String" (optional) 858 Describes the intended purpose of a link to an image. If set, the 859 "rel" property MUST be set to "icon". The value MUST be one of 860 the following values, a value registered in the IANA JSCalendar 861 Enum Registry, or a vendor-specific value: 863 * "badge": an image meant to be displayed alongside the title of 864 the object. 866 * "graphic": a full image replacement for the object itself. 868 * "fullsize": an image that is used to enhance the object. 870 * "thumbnail": a smaller variant of "fullsize" to be used when 871 space for the image is constrained. 873 o title: "String" (optional) 875 A human-readable plain-text description of the resource. 877 4.2.8. locale 879 Type: "String" (optional). 881 The language tag as defined in [RFC5646] that best describes the 882 locale used for the text in the calendar object, if known. 884 4.2.9. keywords 886 Type: "String[Boolean]" (optional). 888 A set of keywords or tags that relate to the object. The set is 889 represented as a map, with the keys being the keywords. The value 890 for each key in the map MUST be true. 892 4.2.10. categories 894 Type: "String[Boolean]" (optional). 896 A set of categories that relate to the calendar object. The set is 897 represented as a map, with the keys being the categories specified as 898 URIs. The value for each key in the map MUST be true. 900 In contrast to keywords, categories typically are structured. For 901 example, a vendor owning the domain "example.com" might define the 902 categories "http://example.com/categories/sports/american-football"" 903 and "http://example.com/categories/music/r-b". 905 4.2.11. color 907 Type: "String" (optional). 909 A color clients MAY use when displaying this calendar object. The 910 value is a color name taken from the set of names defined in 911 Section 4.3 of CSS Color Module Level 3 [COLORS], or an RGB value in 912 hexadecimal notation, as defined in Section 4.2.1 of CSS Color Module 913 Level 3. 915 4.3. Recurrence Properties 917 Some events and tasks occur at regular or irregular intervals. 918 Rather than having to copy the data for every occurrence there can be 919 a master event with a recurrence rule, and/or overrides that add 920 extra dates or exceptions to the rule. 922 4.3.1. recurrenceId 924 Type: "LocalDateTime" (optional). 926 If present, this JSCalendar object represents one occurrence of a 927 recurring JSCalendar object. If present the "recurrenceRules" and 928 "recurrenceOverrides" properties MUST NOT be present. 930 The value is a date-time either produced by the "recurrenceRules" of 931 the master event, or added as a key to the "recurrenceOverrides" 932 property of the master event. 934 4.3.2. recurrenceRules 936 Type: "RecurrenceRule[]" (optional). 938 Defines a set of recurrence rules (repeating patterns) for recurring 939 calendar objects. 941 A JSEvent recurs by applying the recurrence rules to the "start" 942 date-time. 944 A JSTask recurs by applying the recurrence rules to the "start" date- 945 time, if defined, otherwise it recurs by the "due" date-time, if 946 defined. If the task defines neither a "start" nor "due" date-time, 947 it MUST NOT define a "recurrenceRules" property. 949 If multiple recurrence rules are given, each rule is to be applied 950 and then the union of the results used, ignoring any duplicates. 952 A RecurrenceRule object is a JSON object mapping of a RECUR value 953 type in iCalendar [RFC5545] [RFC7529] and has the same semantics. It 954 has the following properties: 956 o @type: "String" (mandatory) 958 Specifies the type of this object. This MUST be "RecurrenceRule". 960 o frequency: "String" (mandatory) 962 The time span covered by each iteration of this recurrence rule 963 (see Section 4.3.2.1 for full semantics). This MUST be one of the 964 following values: 966 * "yearly" 968 * "monthly" 970 * "weekly" 972 * "daily" 974 * "hourly" 976 * "minutely" 978 * "secondly" 980 This is the FREQ part from iCalendar, converted to lowercase. 982 o interval: "UnsignedInt" (optional, default: 1) 984 The interval of iteration periods at which the recurrence repeats. 985 If included, it MUST be an integer >= 1. 987 This is the INTERVAL part from iCalendar. 989 o rscale: "String" (optional, default: "gregorian") 991 The calendar system in which this recurrence rule operates, in 992 lowercase. This MUST be either a CLDR-registered calendar system 993 name [CLDR], or a vendor-specific value. 995 This is the RSCALE part from iCalendar RSCALE [RFC7529], converted 996 to lowercase. 998 o skip: "String" (optional, default: "omit") 1000 The behaviour to use when the expansion of the recurrence produces 1001 invalid dates. This property only has an effect if the frequency 1002 is "yearly" or "monthly". It MUST be one of the following values: 1004 * "omit" 1006 * "backward" 1008 * "forward" 1010 This is the SKIP part from iCalendar RSCALE [RFC7529], converted 1011 to lowercase. 1013 o firstDayOfWeek: "String" (optional, default: "mo") 1015 The day on which the week is considered to start, represented as a 1016 lowercase abbreviated two-letter English day of the week. If 1017 included, it MUST be one of the following values: 1019 * "mo" 1021 * "tu" 1023 * "we" 1025 * "th" 1027 * "fr" 1029 * "sa" 1031 * "su" 1033 This is the WKST part from iCalendar. 1035 o byDay: "NDay[]" (optional) 1037 Days of the week on which to repeat. An *NDay* object has the 1038 following properties: 1040 * day: "String" (mandatory) 1042 A day of the week on which to repeat; the allowed values are 1043 the same as for the "firstDayOfWeek" RecurrenceRule property. 1045 This is the day-of-the-week of the BYDAY part in iCalendar, 1046 converted to lowercase. 1048 * nthOfPeriod: "Int" (optional) 1050 If present, rather than representing every occurrence of the 1051 weekday defined in the "day" property, it represents only a 1052 specific instance within the recurrence period. The value can 1053 be positive or negative, but MUST NOT be zero. A negative 1054 integer means nth-last of period. 1056 This is the ordinal part of the BYDAY value in iCalendar (e.g., 1057 1 or -3). 1059 o byMonthDay: "Int[]" (optional) 1061 Days of the month on which to repeat. Valid values are between 1 1062 and the maximum number of days any month may have in the calendar 1063 given by the "rscale" property, and the negative values of these 1064 numbers. For example, in the Gregorian calendar valid values are 1065 1 to 31 and -31 to -1. Negative values offset from the end of the 1066 month. The array MUST have at least one entry if included. 1068 This is the BYMONTHDAY part in iCalendar. 1070 o byMonth: "String[]" (optional) 1072 The months in which to repeat. Each entry is a string 1073 representation of a number, starting from "1" for the first month 1074 in the calendar (e.g., "1" means January with the Gregorian 1075 calendar), with an optional "L" suffix (see [RFC7529]) for leap 1076 months (this MUST be uppercase, e.g., "3L"). The array MUST have 1077 at least one entry if included. 1079 This is the BYMONTH part from iCalendar. 1081 o byYearDay: "Int[]" (optional) 1083 The days of the year on which to repeat. Valid values are between 1084 1 and the maximum number of days any year may have in the calendar 1085 given by the "rscale" property, and the negative values of these 1086 numbers. For example, in the Gregorian calendar valid values are 1087 1 to 366 and -366 to -1. Negative values offset from the end of 1088 the year. The array MUST have at least one entry if included. 1090 This is the BYYEARDAY part from iCalendar. 1092 o byWeekNo: "Int[]" (optional) 1093 Weeks of the year in which to repeat. Valid values are between 1 1094 and the maximum number of weeks any year may have in the calendar 1095 given by the "rscale" property, and the negative values of these 1096 numbers. For example, in the Gregorian calendar valid values are 1097 1 to 53 and -53 to -1. The array MUST have at least one entry if 1098 included. 1100 This is the BYWEEKNO part from iCalendar. 1102 o byHour: "UnsignedInt[]" (optional) 1104 The hours of the day in which to repeat. Valid values are 0 to 1105 23. The array MUST have at least one entry if included. This is 1106 the BYHOUR part from iCalendar. 1108 o byMinute: "UnsignedInt[]" (optional) 1110 The minutes of the hour in which to repeat. Valid values are 0 to 1111 59. The array MUST have at least one entry if included. 1113 This is the BYMINUTE part from iCalendar. 1115 o bySecond: "UnsignedInt[]" (optional) 1117 The seconds of the minute in which to repeat. Valid values are 0 1118 to 60. The array MUST have at least one entry if included. 1120 This is the BYSECOND part from iCalendar. 1122 o bySetPosition: "Int[]" (optional) 1124 The occurrences within the recurrence interval to include in the 1125 final results. Negative values offset from the end of the list of 1126 occurrences. The array MUST have at least one entry if included. 1127 This is the BYSETPOS part from iCalendar. 1129 o count: "UnsignedInt" (optional) 1131 The number of occurrences at which to range-bound the recurrence. 1132 This MUST NOT be included if an "until" property is specified. 1134 This is the COUNT part from iCalendar. 1136 o until: "LocalDateTime" (optional) 1138 The date-time at which to finish recurring. The last occurrence 1139 is on or before this date-time. This MUST NOT be included if a 1140 "count" property is specified. Note: if not specified otherwise 1141 for a specific JSCalendar object, this date is to be interpreted 1142 in the time zone specified in the JSCalendar object's "timeZone" 1143 property. 1145 This is the UNTIL part from iCalendar. 1147 4.3.2.1. Interpreting recurrence rules 1149 A recurrence rule specifies a set of date-times for recurring 1150 calendar objects. A recurrence rule has the following semantics. 1151 Note, wherever "year", "month" or "day of month" is used, this is 1152 within the calendar system given by the "rscale" property, which 1153 defaults to "gregorian" if omitted. 1155 1. A set of candidates is generated. This is every second within a 1156 period defined by the frequency property value: 1158 * "yearly": every second from midnight on the 1st day of a year 1159 (inclusive) to midnight the 1st day of the following year 1160 (exclusive). 1162 If skip is not "omit", the calendar system has leap months and 1163 there is a byMonth property, generate candidates for the leap 1164 months even if they don't occur in this year. 1166 If skip is not "omit" and there is a byMonthDay property, 1167 presume each month has the maximum number of days any month 1168 may have in this calendar system when generating candidates, 1169 even if it's more than this month actually has. 1171 * "monthly": every second from midnight on the 1st day of a 1172 month (inclusive) to midnight on the 1st of the following 1173 month (exclusive). 1175 If skip is not "omit" and there is a byMonthDay property, 1176 presume the month has the maximum number of days any month may 1177 have in this calendar system when generating candidates, even 1178 if it's more than this month actually has. 1180 * "weekly": every second from midnight (inclusive) on the first 1181 day of the week (as defined by the firstDayOfWeek property, or 1182 Monday if omitted), to midnight 7 days later (exclusive). 1184 * "daily": every second from midnight at the start of the day 1185 (inclusive) to midnight at the end of the day (exclusive). 1187 * "hourly": every second from the beginning of the hour 1188 (inclusive) to the beginning of the next hour (exclusive). 1190 * "minutely": every second from the beginning of the minute 1191 (inclusive) to the beginning of the next minute (exclusive). 1193 * "secondly": the second itself, only. 1195 2. Each date-time candidate is compared against all of the byX 1196 properties of the rule except bySetPosition. If any property in 1197 the rule does not match the date-time, it is eliminated. Each 1198 byX property is an array; the date-time matches the property if 1199 it matches any of the values in the array. The properties have 1200 the following semantics: 1202 * byMonth: the date-time is in the given month. 1204 * byWeekNo: the date-time is in the nth week of the year. 1205 Negative numbers mean the nth last week of the year. This 1206 corresponds to weeks according to week numbering as defined in 1207 ISO.8601.2004, with a week defined as a seven day period, 1208 starting on the firstDayOfWeek property value or Monday if 1209 omitted. Week number one of the calendar year is the first 1210 week that contains at least four days in that calendar year. 1212 If the date-time is not valid (this may happen when generating 1213 candidates with a skip property in effect), it is always 1214 eliminated by this property. 1216 * byYearDay: the date-time is on the nth day of year. Negative 1217 numbers mean the nth last day of the year. 1219 If the date-time is not valid (this may happen when generating 1220 candidates with a skip property in effect), it is always 1221 eliminated by this property. 1223 * byMonthDay: the date-time is on the given day of the month. 1224 Negative numbers mean the nth last day of the month. 1226 * byDay: the date-time is on the given day of the week. If the 1227 day is prefixed by a number, it is the nth occurrence of that 1228 day of the week within the month (if frequency is monthly) or 1229 year (if frequency is yearly). Negative numbers means nth 1230 last occurrence within that period. 1232 * byHour: the date-time has the given hour value. 1234 * byMinute: the date-time has the given minute value. 1236 * bySecond: the date-time has the given second value. 1238 If a skip property is defined and is not "omit", there may be 1239 candidates that do not correspond to valid dates (e.g., 31st 1240 February in the Gregorian calendar). In this case, the 1241 properties MUST be considered in the order above and: 1243 1. After applying the byMonth filter, if the candidate's month 1244 is invalid for the given year, increment it (if skip is 1245 "forward") or decrement it (if skip is "backward") until a 1246 valid month is found, incrementing/decrementing the year as 1247 well if passing through the beginning/end of the year. This 1248 only applies to calendar systems with leap months. 1250 2. After applying the byMonthDay filter, if the day of the month 1251 is invalid for the given month and year, change the date to 1252 the first day of the next month (if skip is "forward") or the 1253 last day of the current month (if skip is "backward"). 1255 3. If any valid date produced after applying the skip is already 1256 a candidate, eliminate the duplicate. (For example after 1257 adjusting, 30th February and 31st February would both become 1258 the same "real" date, so one is eliminated as a duplicate.) 1260 3. If a bySetPosition property is included, this is now applied to 1261 the ordered list of remaining dates. This property specifies the 1262 indexes of date-times to keep; all others should be eliminated. 1263 Negative numbers are indexes from the end of the list, with -1 1264 being the last item. 1266 4. Any date-times before the start date of the event are eliminated 1267 (see below for why this might be needed). 1269 5. If a skip property is included and is not "omit", eliminate any 1270 date-times that have already been produced by previous iterations 1271 of the algorithm. (This is not possible if skip is "omit".) 1273 6. If further dates are required (we have not reached the until 1274 date, or count limit) skip the next (interval - 1) sets of 1275 candidates, then continue from step 1. 1277 When determining the set of occurrence dates for an event or task, 1278 the following extra rules must be applied: 1280 1. The initial date-time to which the rule is applied (the "start" 1281 date-time for events; the "start" or "due" date-time for tasks) 1282 is always the first occurrence in the expansion (and is counted 1283 if the recurrence is limited by a "count" property), even if it 1284 would normally not match the rule. 1286 2. The first set of candidates to consider is that which would 1287 contain the initial date-time. This means the first set may 1288 include candidates before the initial date-time; such candidates 1289 are eliminated from the results in step (4) as outlined before. 1291 3. The following properties MUST be implicitly added to the rule 1292 under the given conditions: 1294 * If frequency is not "secondly" and no bySecond property: Add a 1295 bySecond property with the sole value being the seconds value 1296 of the initial date-time. 1298 * If frequency is not "secondly" or "minutely", and no byMinute 1299 property: Add a byMinute property with the sole value being 1300 the minutes value of the initial date-time. 1302 * If frequency is not "secondly", "minutely" or "hourly" and no 1303 byHour property: Add a byHour property with the sole value 1304 being the hours value of the initial date-time. 1306 * If frequency is "weekly" and no byDay property: Add a byDay 1307 property with the sole value being the day-of-the-week of the 1308 initial date-time. 1310 * If frequency is "monthly" and no byDay property and no 1311 byMonthDay property: Add a byMonthDay property with the sole 1312 value being the day-of-the-month of the initial date-time. 1314 * If frequency is "yearly" and no byYearDay property: 1316 + If there are no byMonth or byWeekNo properties, and either 1317 there is a byMonthDay property or there is no byDay 1318 property: Add a byMonth property with the sole value being 1319 the month of the initial date-time. 1321 + If there is no byMonthDay, byWeekNo or byDay properties: 1322 Add a byMonthDay property with the sole value being the 1323 day-of-the-month of the initial date-time. 1325 + If there is a byWeekNo property and no byMonthDay or byDay 1326 properties: Add a byDay property with the sole value being 1327 the day-of-the-week of the initial date-time. 1329 4.3.3. recurrenceOverrides 1331 Type: "LocalDateTime[PatchObject]" (optional). 1333 A map of the recurrence ids (the date-time produced by the recurrence 1334 rule) to an object of patches to apply to the generated occurrence 1335 object. 1337 If the recurrence id does not match a date-time from the recurrence 1338 rule (or no rule is specified), it is to be treated as an additional 1339 occurrence (like an RDATE from iCalendar). The patch object may 1340 often be empty in this case. 1342 If the patch object defines the "excluded" property value to be true, 1343 then the recurring calendar object does not occur at the recurrence 1344 id date-time (like an EXDATE from iCalendar). Such a patch object 1345 MUST NOT patch any other property. 1347 By default, an occurrence inherits all properties from the main 1348 object except the start (or due) date-time, which is shifted to match 1349 the recurrence id LocalDateTime. However, individual properties of 1350 the occurrence can be modified by a patch, or multiple patches. It 1351 is valid to patch the "start" property value, and this patch takes 1352 precedence over the value generated from the recurrence id. Both the 1353 recurrence id as well as the patched "start" date-time may occur 1354 before the original JSCalendar object's "start" or "due" date. 1356 A pointer in the PatchObject MUST be ignored if it starts with one of 1357 the following prefixes: 1359 o @type 1361 o method 1363 o privacy 1365 o prodId 1367 o recurrenceId 1369 o recurrenceOverrides 1371 o recurrenceRules 1373 o relatedTo 1375 o replyTo 1377 o uid 1379 4.3.4. excluded 1381 Type: "Boolean" (optional, default: false). 1383 Defines if this object is an overridden, excluded instance of a 1384 recurring JSCalendar object (see Section 4.3.3). If this property 1385 value is true, this calendar object instance MUST be removed from the 1386 occurrence expansion. The absence of this property or its default 1387 value false indicates that this instance MUST be included in the 1388 occurrence expansion. 1390 4.4. Sharing and Scheduling Properties 1392 4.4.1. priority 1394 Type: "Int" (optional, default: 0). 1396 Specifies a priority for the calendar object. This may be used as 1397 part of scheduling systems to help resolve conflicts for a time 1398 period. 1400 The priority is specified as an integer in the range 0 to 9. A value 1401 of 0 specifies an undefined priority. A value of 1 is the highest 1402 priority. A value of 2 is the second highest priority. Subsequent 1403 numbers specify a decreasing ordinal priority. A value of 9 is the 1404 lowest priority. Other integer values are reserved for future use. 1406 4.4.2. freeBusyStatus 1408 Type: "String" (optional, default: "busy"). 1410 Specifies how this calendar object should be treated when calculating 1411 free-busy state. This MUST be one of the following values, a value 1412 registered in the IANA JSCalendar Enum Registry, or a vendor-specific 1413 value: 1415 o "free": The object should be ignored when calculating whether the 1416 user is busy. 1418 o "busy": The object should be included when calculating whether the 1419 user is busy. 1421 4.4.3. privacy 1423 Type: "String" (optional, default: "public"). 1425 Calendar objects are normally collected together and may be shared 1426 with other users. The privacy property allows the object owner to 1427 indicate that it should not be shared, or should only have the time 1428 information shared but the details withheld. Enforcement of the 1429 restrictions indicated by this property are up to the API via which 1430 this object is accessed. 1432 This property MUST NOT affect the information sent to scheduled 1433 participants; it is only interpreted when the object is shared as 1434 part of a shared calendar. 1436 The value MUST be one of the following values, a value registered in 1437 the IANA JSCalendar Enum Registry, or a vendor-specific value. Any 1438 value the client or server doesn't understand should be preserved but 1439 treated as equivalent to "private". 1441 o "public": The full details of the object are visible to those whom 1442 the object's calendar is shared with. 1444 o "private": The details of the object are hidden; only the basic 1445 time and metadata is shared. The following properties MAY be 1446 shared, any other properties MUST NOT be shared: 1448 * @type 1450 * created 1452 * due 1454 * duration 1456 * estimatedDuration 1458 * freeBusyStatus 1460 * privacy 1462 * recurrenceOverrides. Only patches which apply to another 1463 permissible property are allowed to be shared. 1465 * sequence 1467 * showWithoutTime 1469 * start 1471 * timeZone 1473 * timeZones 1474 * uid 1476 * updated 1478 o "secret": The object is hidden completely (as though it did not 1479 exist) when the calendar this object is in is shared. 1481 4.4.4. replyTo 1483 Type: "String[String]" (optional). 1485 Represents methods by which participants may submit their RSVP 1486 response to the organizer of the calendar object. The keys in the 1487 property value are the available methods and MUST only contain ASCII 1488 alphanumeric characters (A-Za-z0-9). The value is a URI for the 1489 method specified in the key. Future methods may be defined in future 1490 specifications and registered with IANA; a calendar client MUST 1491 ignore any method it does not understand, but MUST preserve the 1492 method key and URI. This property MUST be omitted if no method is 1493 defined (rather than being specified as an empty object). If this 1494 property is set, the "participants" property of this calendar object 1495 MUST contain at least one participant. 1497 The following methods are defined: 1499 o "imip": The organizer accepts an iMIP [RFC6047] response at this 1500 email address. The value MUST be a "mailto:" URI. 1502 o "web": Opening this URI in a web browser will provide the user 1503 with a page where they can submit a reply to the organizer. 1505 o "other": The organizer is identified by this URI the method for 1506 submitting the response is undefined. 1508 4.4.5. participants 1510 Type: "Id[Participant]" (optional). 1512 A map of participant ids to participants, describing their 1513 participation in the calendar object. 1515 If this property is set, then the "replyTo" property of this calendar 1516 object MUST define at least one reply method. 1518 A Participant object has the following properties: 1520 o @type: "String" (mandatory) 1521 Specifies the type of this object. This MUST be "Participant". 1523 o name: "String" (optional) 1525 The display name of the participant (e.g., "Joe Bloggs"). 1527 o email: "String" (optional) 1529 The email address for the participant. 1531 o sendTo: "String[String]" (optional) 1533 Represents methods by which the participant may receive the 1534 invitation and updates to the calendar object. 1536 The keys in the property value are the available methods and MUST 1537 only contain ASCII alphanumeric characters (A-Za-z0-9). The value 1538 is a URI for the method specified in the key. Future methods may 1539 be defined in future specifications and registered with IANA; a 1540 calendar client MUST ignore any method it does not understand, but 1541 MUST preserve the method key and URI. This property MUST be 1542 omitted if no method is defined (rather than being specified as an 1543 empty object). 1545 The following methods are defined: 1547 * "imip": The participant accepts an iMIP [RFC6047] request at 1548 this email address. The value MUST be a "mailto:" URI. It MAY 1549 be different from the value of the participant's "email" 1550 property. 1552 * "other": The participant is identified by this URI but the 1553 method for submitting the invitation is undefined. 1555 o kind: "String" (optional) 1557 What kind of entity this participant is, if known. 1559 This MUST be one of the following values, a value registered in 1560 the IANA JSCalendar Enum Registry, or a vendor-specific value. 1561 Any value the client or server doesn't understand should be 1562 treated the same as if this property is omitted. 1564 * "individual": a single person 1566 * "group": a collection of people invited as a whole 1567 * "location": a physical location that needs to be scheduled, 1568 e.g., a conference room 1570 * "resource": a non-human resource other than a location, such as 1571 a projector 1573 o roles: "String[Boolean]" (mandatory) 1575 A set of roles that this participant fulfills. 1577 At least one role MUST be specified for the participant. The keys 1578 in the set MUST be one of the following values, a value registered 1579 in the IANA JSCalendar Enum Registry, or a vendor-specific value: 1581 * "owner": The participant is an owner of the object. This 1582 signifies they have permission to make changes to it that 1583 affect the other participants. Non-owner participants may only 1584 change properties that just affect themself (for example 1585 setting their own alerts or changing their rsvp status). 1587 * "attendee": The participant is expected to attend. 1589 * "optional": The participant is invited but not required. 1591 * "informational": The participant is copied for informational 1592 reasons, and is not expected to attend. 1594 * "chair": The participant is in charge of the event/task when it 1595 occurs. 1597 The value for each key in the set MUST be true. It is expected 1598 that no more than one of the roles "attendee", "optional", or 1599 "informational" be present; if more than one are given, "optional" 1600 takes precedence over "informational", and "attendee" takes 1601 precedence over both. Roles that are unknown to the 1602 implementation MUST be preserved. 1604 o locationId: "String" (optional) 1606 The location at which this participant is expected to be 1607 attending. 1609 If the value does not correspond to any location id in the 1610 "locations" property of the JSCalendar object, this MUST be 1611 treated the same as if the participant's locationId were omitted. 1613 o language: "String" (optional) 1614 The language tag as defined in [RFC5646] that best describes the 1615 participant's preferred language, if known. 1617 o participationStatus: "String" (optional, default: "needs-action") 1619 The participation status, if any, of this participant. 1621 The value MUST be one of the following values, a value registered 1622 in the IANA JSCalendar Enum Registry, or a vendor-specific value: 1624 * "needs-action": No status yet set by the participant. 1626 * "accepted": The invited participant will participate. 1628 * "declined": The invited participant will not participate. 1630 * "tentative": The invited participant may participate. 1632 * "delegated": The invited participant has delegated their 1633 attendance to another participant, as specified in the 1634 delegatedTo property. 1636 o participationComment: "String" (optional) 1638 A note from the participant to explain their participation status. 1640 o expectReply: "Boolean" (optional, default: false) 1642 If true, the organizer is expecting the participant to notify them 1643 of their participation status. 1645 o scheduleAgent: "String" (optional, default: "server") 1647 Who is responsible for sending scheduling messages with this 1648 calendar object to the participant. 1650 The value MUST be one of the following values, a value registered 1651 in the IANA JSCalendar Enum Registry, or a vendor-specific value: 1653 * "server": The calendar server will send the scheduling 1654 messages. 1656 * "client": The calendar client will send the scheduling 1657 messages. 1659 * "none": No scheduling messages are to be sent to this 1660 participant. 1662 o scheduleSequence: "UnsignedInt" (optional, default: 0) 1664 The sequence number of the last response from the participant. If 1665 defined, this MUST be a non-negative integer. 1667 This can be used to determine whether the participant has sent a 1668 new RSVP following significant changes to the calendar object, and 1669 to determine if future responses are responding to a current or 1670 older view of the data. 1672 o scheduleUpdated: "UTCDateTime" (optional) 1674 The "updated" property of the last iTIP response from the 1675 participant. 1677 This can be compared to the "updated" property timestamp in future 1678 iTIP responses to determine if the response is older or newer than 1679 the current data. 1681 o invitedBy: "String" (optional) 1683 The participant id of the participant who invited this one, if 1684 known. 1686 o delegatedTo: "String[Boolean]" (optional) 1688 A set of participant ids that this participant has delegated their 1689 participation to. Each key in the set MUST be the id of a 1690 participant. The value for each key in the set MUST be true. If 1691 there are no delegates, this MUST be omitted (rather than 1692 specified as an empty set). 1694 o delegatedFrom: "String[Boolean]" (optional) 1696 A set of participant ids that this participant is acting as a 1697 delegate for. Each key in the set MUST be the id of a 1698 participant. The value for each key in the set MUST be true. If 1699 there are no delegators, this MUST be omitted (rather than 1700 specified as an empty set). 1702 o memberOf: "String[Boolean]" (optional) 1704 A set of group participants that were invited to this calendar 1705 object, which caused this participant to be invited due to their 1706 membership in the group(s). Each key in the set MUST be the id of 1707 a participant. The value for each key in the set MUST be true. 1708 If there are no groups, this MUST be omitted (rather than 1709 specified as an empty set). 1711 o linkIds: "String[Boolean]" (optional) 1713 A set of links to more information about this participant, for 1714 example in vCard format. The keys in the set MUST be the id of a 1715 Link object in the calendar object's "links" property. The value 1716 for each key in the set MUST be true. If there are no links, this 1717 MUST be omitted (rather than specified as an empty set). 1719 o progress: "String" (optional). This is only allowed if the 1720 Participant is part of a JSTask. It represents the progress of 1721 the participant for this task, if known. This property MUST NOT 1722 be set if the "participationStatus" of this participant is any 1723 value other than "accepted". See Section 5.2.4 for allowed values 1724 and semantics. 1726 o progressUpdated: "UTCDateTime" (optional). Specifies the date- 1727 time the progress property was last set on this participant. This 1728 is only allowed if the Participant is part of a JSTask. 1730 4.5. Alerts Properties 1732 4.5.1. useDefaultAlerts 1734 Type: "Boolean" (optional, default: false). 1736 If true, use the user's default alerts and ignore the value of the 1737 "alerts" property. Fetching user defaults is dependent on the API 1738 from which this JSCalendar object is being fetched, and is not 1739 defined in this specification. If an implementation cannot determine 1740 the user's default alerts, or none are set, it MUST process the 1741 alerts property as if "useDefaultAlerts" is set to false. 1743 4.5.2. alerts 1745 Type: "Id[Alert]" (optional). 1747 A map of alert ids to Alert objects, representing alerts/reminders to 1748 display or send to the user for this calendar object. 1750 An Alert Object has the following properties: 1752 o @type: "String" (mandatory) 1754 Specifies the type of this object. This MUST be "Alert". 1756 o trigger: "OffsetTrigger|AbsoluteTrigger|UnknownTrigger" 1757 (mandatory) 1758 Defines when to trigger the alert. New types may be defined in 1759 future documents. 1761 An *OffsetTrigger* object has the following properties: 1763 * @type: "String" (mandatory) 1765 Specifies the type of this object. This MUST be 1766 "OffsetTrigger". 1768 * offset: "SignedDuration" (mandatory). 1770 Defines the offset at which to trigger the alert relative to 1771 the time property defined in the "relativeTo" property of the 1772 alert. Negative durations signify alerts before the time 1773 property, positive durations signify alerts after. If the 1774 calendar object does not define a time zone, the user's default 1775 time zone SHOULD be used when determining the offset, if known. 1776 Otherwise, the time zone to use is implementation specific. 1778 * relativeTo: "String" (optional, default: "start") 1780 Specifies the time property that the alert offset is relative 1781 to. The value MUST be one of: 1783 + "start": triggers the alert relative to the start of the 1784 calendar object 1786 + "end": triggers the alert relative to the end/due time of 1787 the calendar object 1789 An *AbsoluteTrigger* object has the following properties: 1791 * @type: "String" (mandatory) 1793 Specifies the type of this object. This MUST be 1794 "AbsoluteTrigger". 1796 * when: "UTCDateTime" (mandatory). 1798 Defines a specific UTC date-time when the alert is triggered. 1800 An *UnknownTrigger* object is an object that contains a *@type* 1801 property whose value is not recognized (i.e., not "OffsetTrigger" 1802 or "AbsoluteTrigger"), plus zero or more other properties. This 1803 is for compatibility with client extensions and future 1804 specifications. Implementations SHOULD NOT trigger for trigger 1805 types they do not understand, but MUST preserve them. 1807 o acknowledged: "UTCDateTime" (optional) 1809 This records when an alert was last acknowledged. This is set 1810 when the user has dismissed the alert; other clients that sync 1811 this property SHOULD automatically dismiss or suppress duplicate 1812 alerts (alerts with the same alert id that triggered on or before 1813 this date-time). 1815 For a recurring calendar object, the "acknowledged" property of 1816 the parent object MUST be updated, unless the alert is already 1817 overridden in the "recurrenceOverrides" property. 1819 Certain kinds of alert action may not provide feedback as to when 1820 the user sees them, for example email based alerts. For those 1821 kinds of alerts, this property SHOULD be set immediately when the 1822 alert is triggered and the action successfully carried out. 1824 o relatedTo: "String[Relation]" (optional) 1826 Relates this alert to other alerts in the same JSCalendar object. 1827 If the user wishes to snooze an alert, the application SHOULD 1828 create an alert to trigger after snoozing. All snooze alerts 1829 SHOULD set a relation to the identifier of the original alert. 1830 The Relation object SHOULD set the "parent" relation type. 1832 o action: "String" (optional, default: "display") 1834 Describes how to alert the user. 1836 The value MUST be at most one of the following values, a value 1837 registered in the IANA JSCalendar Enum Registry, or a vendor- 1838 specific value: 1840 * "display": The alert should be displayed as appropriate for the 1841 current device and user context. 1843 * "email": The alert should trigger an email sent out to the 1844 user, notifying about the alert. This action is typically only 1845 appropriate for server implementations. 1847 4.6. Multilingual Properties 1849 4.6.1. localizations 1851 Type: "String[PatchObject]" (optional). 1853 A map of language tags [RFC5646] to patch objects, which localize the 1854 calendar object into the locale of the respective language tag. 1856 See the description of PatchObject (Section 1.4.8) for the structure 1857 of the PatchObject. The patches are applied to the top-level 1858 calendar object. In addition, the "locale" property of the patched 1859 object is set to the language tag. All pointers for patches MUST end 1860 with one of the following suffixes; any patch that does not follow 1861 this MUST be ignored unless otherwise specified in a future RFC: 1863 o title 1865 o description 1867 o name 1869 A patch MUST NOT have the prefix "recurrenceOverrides"; any 1870 localization of the override MUST be a patch to the localizations 1871 property inside the override instead. For example, a patch to 1872 "locations/abcd1234/title" is permissible, but a patch to "uid" or 1873 "recurrenceOverrides/2018-01-05T14:00:00/title" is not. 1875 Note that this specification does not define how to maintain validity 1876 of localized content. For example, a client application changing a 1877 JSCalendar object's title property might also need to update any 1878 localizations of this property. Client implementations SHOULD 1879 provide the means to manage localizations, but how to achieve this is 1880 specific to the application's workflow and requirements. 1882 4.7. Time Zone Properties 1884 4.7.1. timeZone 1886 Type: "String|null" (optional, default: null). 1888 Identifies the time zone the object is scheduled in, or null for 1889 floating time. This is either a name from the IANA Time Zone 1890 Database [TZDB] or the id of a custom time zone from the "timeZones" 1891 property (see Section 1.4.9). If omitted, this MUST be presumed to 1892 be null (i.e., floating time). 1894 4.7.2. timeZones 1896 Type: "String[TimeZone]" (optional). 1898 Maps identifiers of custom time zones to their time zone definitions. 1899 The following restrictions apply for each key in the map: 1901 o It MUST start with the "/" character (ASCII decimal 47; also see 1902 Sections 3.2.19 of [RFC5545] and 3.6. of [RFC7808] for discussion 1903 of the forward slash character in time zone identifiers). 1905 o It MUST be a valid "paramtext" value as specified in Section 3.1. 1906 of [RFC5545]. 1908 o At least one other property in the same JSCalendar object MUST 1909 reference a time zone using this identifier (i.e., orphaned time 1910 zones are not allowed). 1912 An identifier need only be unique to this JSCalendar object. 1914 A TimeZone object maps a VTIMEZONE component from iCalendar [RFC5545] 1915 and the semantics are as defined there. A valid time zone MUST 1916 define at least one transition rule in the "standard" or "daylight" 1917 property. Its properties are: 1919 o @type: "String" (mandatory) 1921 Specifies the type of this object. This MUST be "TimeZone". 1923 o tzId: "String" (mandatory). 1925 The TZID property from iCalendar. 1927 o lastModified: "UTCDateTime" (optional) 1929 The LAST-MODIFIED property from iCalendar. 1931 o url: "String" (optional) 1933 The TZURL property from iCalendar. 1935 o validUntil: "UTCDateTime" (optional) 1937 The TZUNTIL property from iCalendar specified in [RFC7808]. 1939 o aliases: "String[Boolean]" (optional) 1941 Maps the TZID-ALIAS-OF properties from iCalendar specified in 1942 [RFC7808] to a JSON set of aliases. The set is represented as an 1943 object, with the keys being the aliases. The value for each key 1944 in the set MUST be true. 1946 o standard: "TimeZoneRule[]" (optional) 1948 The STANDARD sub-components from iCalendar. The order MUST be 1949 preserved during conversion. 1951 o daylight: "TimeZoneRule[]" (optional). 1953 The DAYLIGHT sub-components from iCalendar. The order MUST be 1954 preserved during conversion. 1956 A TimeZoneRule object maps a STANDARD or DAYLIGHT sub-component from 1957 iCalendar, with the restriction that at most one recurrence rule is 1958 allowed per rule. It has the following properties: 1960 o @type: "String" (mandatory) 1962 Specifies the type of this object. This MUST be "TimeZoneRule". 1964 o start: "LocalDateTime" (mandatory) 1966 The DTSTART property from iCalendar. 1968 o offsetTo: "String" (mandatory) 1970 The TZOFFSETTO property from iCalendar. 1972 o offsetFrom: "String" (mandatory) 1974 The TZOFFSETFROM property from iCalendar. 1976 o recurrenceRule: "RecurrenceRule" (optional) 1978 The RRULE property mapped as specified in Section 4.3.2. During 1979 recurrence rule evaluation, the "until" property value MUST be 1980 interpreted as a local time in the UTC time zone. 1982 o recurrenceDates: "LocalDateTime[Boolean]" (optional) 1984 Maps the RDATE properties from iCalendar to a JSON set. The set 1985 is represented as an object, with the keys being the recurrence 1986 dates. The value for each key in the set MUST be true. 1988 o names: "String[Boolean]" (optional) 1990 Maps the TZNAME properties from iCalendar to a JSON set. The set 1991 is represented as an object, with the keys being the names. The 1992 value for each key in the set MUST be true. 1994 o comments: "String[]" (optional). Maps the COMMENT properties from 1995 iCalendar. The order MUST be preserved during conversion. 1997 5. Type-specific JSCalendar Properties 1999 5.1. JSEvent Properties 2001 In addition to the common JSCalendar object properties (Section 4) a 2002 JSEvent has the following properties: 2004 5.1.1. start 2006 Type: "LocalDateTime" (mandatory). 2008 The date/time the event starts in the event's time zone (as specified 2009 in the "timeZone" property, see Section 4.7.1). 2011 5.1.2. duration 2013 Type: "Duration" (optional, default: "PT0S"). 2015 The zero or positive duration of the event in the event's start time 2016 zone. 2018 Note that a duration specified using weeks or days does not always 2019 correspond to an exact multiple of 24 hours. The number of 2020 hours/minutes/seconds may vary if it overlaps a period of 2021 discontinuity in the event's time zone, for example a change from 2022 standard time to daylight-savings time. Leap seconds MUST NOT be 2023 considered when computing an exact duration. When computing an exact 2024 duration, the greatest order time components MUST be added first, 2025 that is, the number of days MUST be added first, followed by the 2026 number of hours, number of minutes, and number of seconds. 2027 Fractional seconds MUST be added last. These semantics match the 2028 iCalendar DURATION value type ([RFC5545], Section 3.3.6). 2030 A JSEvent MAY involve start and end locations that are in different 2031 time zones (e.g., a trans-continental flight). This can be expressed 2032 using the "relativeTo" and "timeZone" properties of the JSEvent's 2033 Location objects (see Section 4.2.5). 2035 5.1.3. status 2037 Type: "String" (optional, default: "confirmed"). 2039 The scheduling status (Section 4.4) of a JSEvent. If set, it MUST be 2040 one of the following values, a value registered in the IANA 2041 JSCalendar Enum Registry, or a vendor-specific value: 2043 o "confirmed": Indicates the event is definitely happening. 2045 o "cancelled": Indicates the event has been cancelled. 2047 o "tentative": Indicates the event may happen. 2049 5.2. JSTask Properties 2051 In addition to the common JSCalendar object properties (Section 4) a 2052 JSTask has the following properties: 2054 5.2.1. due 2056 Type: "LocalDateTime" (optional). 2058 The date/time the task is due in the task's time zone. 2060 5.2.2. start 2062 Type: "LocalDateTime" (optional). 2064 The date/time the task should start in the task's time zone. 2066 5.2.3. estimatedDuration 2068 Type: "Duration" (optional). 2070 Specifies the estimated positive duration of time the task takes to 2071 complete. 2073 5.2.4. progress 2075 Type: "String" (optional). 2077 Defines the progress of this task. If omitted, the default progress 2078 (Section 4.4) of a JSTask is defined as follows (in order of 2079 evaluation): 2081 o "completed": if the "progress" property value of all participants 2082 is "completed". 2084 o "failed": if at least one "progress" property value of a 2085 participant is "failed". 2087 o "in-process": if at least one "progress" property value of a 2088 participant is "in-process". 2090 o "needs-action": If none of the other criteria match. 2092 If set, it MUST be one of the following values, a value registered in 2093 the IANA JSCalendar Enum Registry, or a vendor-specific value: 2095 o "needs-action": Indicates the task needs action. 2097 o "in-process": Indicates the task is in process. 2099 o "completed": Indicates the task is completed. 2101 o "failed": Indicates the task failed. 2103 o "cancelled": Indicates the task was cancelled. 2105 5.2.5. progressUpdated 2107 Type: "UTCDateTime" (optional). 2109 Specifies the date/time the "progress" property of either the task 2110 overall (Section 5.2.4) or a specific participant (Section 4.4.5) was 2111 last updated. 2113 If the task is recurring and has future instances, a client may want 2114 to keep track of the last progress update timestamp of a specific 2115 task recurrence, but leave other instances unchanged. One way to 2116 achieve this is by overriding the progressUpdated property in the 2117 task "recurrenceOverrides" property. However, this could produce a 2118 long list of timestamps for regularly recurring tasks. An 2119 alternative approach is to split the JSTask into a current, single 2120 instance of JSTask with this instance progress update time and a 2121 future recurring instance. See also Section 4.1.3 on splitting. 2123 5.3. JSGroup Properties 2125 JSGroup supports the following common JSCalendar properties 2126 (Section 4): 2128 o @type 2130 o categories 2132 o color 2134 o created 2136 o description 2138 o descriptionContentType 2139 o keywords 2141 o links 2143 o locale 2145 o prodId 2147 o title 2149 o updated 2151 o uid 2153 In addition, the following JSGroup-specific properties are supported: 2155 5.3.1. entries 2157 Type: "String[JSTask|JSEvent]" (mandatory). 2159 A collection of group members. This is represented as a map of the 2160 "uid" property value to the JSCalendar object member having that uid. 2161 Implementations MUST ignore entries of unknown type. 2163 5.3.2. source 2165 Type: "String" (optional). 2167 The source from which updated versions of this group may be retrieved 2168 from. The value MUST be a URI. 2170 6. Examples 2172 The following examples illustrate several aspects of the JSCalendar 2173 data model and format. The examples may omit mandatory or additional 2174 properties, which is indicated by a placeholder property with key 2175 "...". While most of the examples use calendar event objects, they 2176 are also illustrative for tasks. 2178 6.1. Simple event 2180 This example illustrates a simple one-time event. It specifies a 2181 one-time event that begins on January 15, 2018 at 1pm New York local 2182 time and ends after 1 hour. 2184 { 2185 "@type": "jsevent", 2186 "uid": "2a358cee-6489-4f14-a57f-c104db4dc2f1", 2187 "updated": "2018-01-15T18:00:00Z", 2188 "title": "Some event", 2189 "start": "2018-01-15T13:00:00", 2190 "timeZone": "America/New_York", 2191 "duration": "PT1H" 2192 } 2194 6.2. Simple task 2196 This example illustrates a simple task for a plain to-do item. 2198 { 2199 "@type": "jstask", 2200 "uid": "2a358cee-6489-4f14-a57f-c104db4dc2f2", 2201 "updated": "2018-01-15T18:00:00Z", 2202 "title": "Do something" 2203 } 2205 6.3. Simple group 2207 This example illustrates a simple calendar object group that contains 2208 an event and a task. 2210 { 2211 "@type": "jsgroup", 2212 "uid": "2a358cee-6489-4f14-a57f-c104db4dc343", 2213 "updated": "2018-01-15T18:00:00Z", 2214 "name": "A simple group", 2215 "entries": { 2216 "2a358cee-6489-4f14-a57f-c104db4dc2f1": { 2217 "@type": "jsevent", 2218 "uid": "2a358cee-6489-4f14-a57f-c104db4dc2f1", 2219 "updated": "2018-01-15T18:00:00Z", 2220 "title": "Some event", 2221 "start": "2018-01-15T13:00:00", 2222 "timeZone": "America/New_York", 2223 "duration": "PT1H" 2224 }, 2225 "2a358cee-6489-4f14-a57f-c104db4dc2f2": { 2226 "@type": "jstask", 2227 "uid": "2a358cee-6489-4f14-a57f-c104db4dc2f2", 2228 "updated": "2018-01-15T18:00:00Z", 2229 "title": "Do something" 2230 } 2231 } 2232 } 2234 6.4. All-day event 2236 This example illustrates an event for an international holiday. It 2237 specifies an all-day event on April 1 that occurs every year since 2238 the year 1900. 2240 { 2241 "...": "", 2242 "title": "April Fool's Day", 2243 "showWithoutTime": true, 2244 "start": "1900-04-01T00:00:00", 2245 "duration": "P1D", 2246 "recurrenceRules": [{ 2247 "@type": "RecurrenceRule", 2248 "frequency": "yearly" 2249 }] 2250 } 2252 6.5. Task with a due date 2254 This example illustrates a task with a due date. It is a reminder to 2255 buy groceries before 6pm Vienna local time on January 19, 2018. The 2256 calendar user expects to need 1 hour for shopping. 2258 { 2259 "...": "", 2260 "title": "Buy groceries", 2261 "due": "2018-01-19T18:00:00", 2262 "timeZone": "Europe/Vienna", 2263 "estimatedDuration": "PT1H" 2264 } 2266 6.6. Event with end time-zone 2268 This example illustrates the use of end time-zones by use of an 2269 international flight. The flight starts on April 1, 2018 at 9am in 2270 Berlin local time. The duration of the flight is scheduled at 10 2271 hours 30 minutes. The time at the flights destination is in the same 2272 time-zone as Tokyo. Calendar clients could use the end time-zone to 2273 display the arrival time in Tokyo local time and highlight the time- 2274 zone difference of the flight. The location names can serve as input 2275 for navigation systems. 2277 { 2278 "...": "", 2279 "title": "Flight XY51 to Tokyo", 2280 "start": "2018-04-01T09:00:00", 2281 "timeZone": "Europe/Berlin", 2282 "duration": "PT10H30M", 2283 "locations": { 2284 "2a358cee-6489-4f14-a57f-c104db4dc2f1": { 2285 "@type": "Location", 2286 "rel": "start", 2287 "name": "Frankfurt Airport (FRA)" 2288 }, 2289 "c2c7ac67-dc13-411e-a7d4-0780fb61fb08": { 2290 "@type": "Location", 2291 "rel": "end", 2292 "name": "Narita International Airport (NRT)", 2293 "timeZone": "Asia/Tokyo" 2294 } 2295 } 2296 } 2298 6.7. Floating-time event (with recurrence) 2300 This example illustrates the use of floating-time. Since January 1, 2301 2018, a calendar user blocks 30 minutes every day to practice Yoga at 2302 7am local time, in whatever time-zone the user is located on that 2303 date. 2305 { 2306 "...": "", 2307 "title": "Yoga", 2308 "start": "2018-01-01T07:00:00", 2309 "duration": "PT30M", 2310 "recurrenceRules": [{ 2311 "@type": "RecurrenceRule", 2312 "frequency": "daily" 2313 }] 2314 } 2316 6.8. Event with multiple locations and localization 2318 This example illustrates an event that happens at both a physical and 2319 a virtual location. Fans can see a live concert on premises or 2320 online. The event title and descriptions are localized. 2322 { 2323 "...": "", 2324 "title": "Live from Music Bowl: The Band", 2325 "description": "Go see the biggest music event ever!", 2326 "locale": "en", 2327 "start": "2018-07-04T17:00:00", 2328 "timeZone": "America/New_York", 2329 "duration": "PT3H", 2330 "locations": { 2331 "c0503d30-8c50-4372-87b5-7657e8e0fedd": { 2332 "@type": "Location", 2333 "name": "The Music Bowl", 2334 "description": "Music Bowl, Central Park, New York", 2335 "coordinates": "geo:40.7829,-73.9654" 2336 } 2337 }, 2338 "virtualLocations": { 2339 "6f3696c6-1e07-47d0-9ce1-f50014b0041a": { 2340 "@type": "VirtualLocation", 2341 "name": "Free live Stream from Music Bowl", 2342 "uri": "https://stream.example.com/the_band_2018" 2343 } 2344 }, 2345 "localizations": { 2346 "de": { 2347 "title": "Live von der Music Bowl: The Band!", 2348 "description": "Schau dir das groesste Musikereignis an!", 2349 "virtualLocations/6f3696c6-1e07-47d0-9ce1-f50014b0041a/name": 2350 "Gratis Live-Stream aus der Music Bowl" 2351 } 2352 } 2353 } 2355 6.9. Recurring event with overrides 2357 This example illustrates the use of recurrence overrides. A math 2358 course at a University is held for the first time on January 8, 2018 2359 at 9am London time and occurs every week until June 25, 2018. Each 2360 lecture lasts for one hour and 30 minutes and is located at the 2361 Mathematics department. This event has exceptional occurrences: at 2362 the last occurrence of the course is an exam, which lasts for 2 hours 2363 and starts at 10am. Also, the location of the exam differs from the 2364 usual location. On April 2 no course is held. On January 5 at 2pm 2365 is an optional introduction course, that occurs before the first 2366 regular lecture. 2368 { 2369 "...": "", 2370 "title": "Calculus I", 2371 "start": "2018-01-08T09:00:00", 2372 "timeZone": "Europe/London", 2373 "duration": "PT1H30M", 2374 "locations": { 2375 "2a358cee-6489-4f14-a57f-c104db4dc2f1": { 2376 "@type": "Location", 2377 "title": "Math lab room 1", 2378 "description": "Math Lab I, Department of Mathematics" 2379 } 2380 }, 2381 "recurrenceRules": [{ 2382 "@type": "RecurrenceRule", 2383 "frequency": "weekly", 2384 "until": "2018-06-25T09:00:00" 2385 }], 2386 "recurrenceOverrides": { 2387 "2018-01-05T14:00:00": { 2388 "title": "Introduction to Calculus I (optional)" 2389 }, 2390 "2018-04-02T09:00:00": { 2391 "excluded": "true" 2392 }, 2393 "2018-06-25T09:00:00": { 2394 "title": "Calculus I Exam", 2395 "start": "2018-06-25T10:00:00", 2396 "duration": "PT2H", 2397 "locations": { 2398 "2a358cee-6489-4f14-a57f-c104db4dc2f1": { 2399 "@type": "Location", 2400 "title": "Big Auditorium", 2401 "description": "Big Auditorium, Other Road" 2402 } 2403 } 2404 } 2405 } 2406 } 2408 6.10. Recurring event with participants 2410 This example illustrates scheduled events. A team meeting occurs 2411 every week since January 8, 2018 at 9am Johannesburg time. The event 2412 owner also chairs the event. Participants meet in a virtual meeting 2413 room. An attendee has accepted the invitation, but on March 8, 2018 2414 he is unavailable and declined participation for this occurrence. 2416 { 2417 "...": "", 2418 "title": "FooBar team meeting", 2419 "start": "2018-01-08T09:00:00", 2420 "timeZone": "Africa/Johannesburg", 2421 "duration": "PT1H", 2422 "virtualLocations": { 2423 "2a358cee-6489-4f14-a57f-c104db4dc2f1": { 2424 "@type": "VirtualLocation", 2425 "name": "ChatMe meeting room", 2426 "uri": "https://chatme.example.com?id=1234567" 2427 } 2428 }, 2429 "recurrenceRules": [{ 2430 "@type": "RecurrenceRule", 2431 "frequency": "weekly" 2432 }], 2433 "replyTo": { 2434 "imip": "mailto:6489-4f14-a57f-c1@schedule.example.com" 2435 }, 2436 "participants": { 2437 "dG9tQGZvb2Jhci5xlLmNvbQ": { 2438 "@type": "Participant", 2439 "name": "Tom Tool", 2440 "email": "tom@foobar.example.com", 2441 "sendTo": { 2442 "imip": "mailto:6489-4f14-a57f-c1@calendar.example.com" 2443 }, 2444 "participationStatus": "accepted", 2445 "roles": { 2446 "attendee": true 2447 } 2448 }, 2449 "em9lQGZvb2GFtcGxlLmNvbQ": { 2450 "@type": "Participant", 2451 "name": "Zoe Zelda", 2452 "email": "zoe@foobar.example.com", 2453 "sendTo": { 2454 "imip": "mailto:zoe@foobar.example.com" 2455 }, 2456 "participationStatus": "accepted", 2457 "roles": { 2458 "owner": true, 2459 "attendee": true, 2460 "chair": true 2461 } 2462 }, 2463 "...": "" 2465 }, 2466 "recurrenceOverrides": { 2467 "2018-03-08T09:00:00": { 2468 "participants/dG9tQGZvb2Jhci5xlLmNvbQ/participationStatus": 2469 "declined" 2470 } 2471 } 2472 } 2474 7. Security Considerations 2476 Calendaring and scheduling information is very privacy-sensitive. 2477 The transmission of such information must be done carefully to 2478 protect it from possible threats, such as eavesdropping, replay, 2479 message insertion, deletion, modification, and man-in-the-middle 2480 attacks. This document just defines the data format; such 2481 considerations are primarily the concern of the API or method of 2482 storage and transmission of such files. 2484 7.1. Expanding Recurrences 2486 A recurrence rule may produce infinite occurrences of an event. 2487 Implementations MUST handle expansions carefully to prevent 2488 accidental or deliberate resource exhaustion. 2490 Conversely, a recurrence rule may be specified that does not expand 2491 to anything. It is not always possible to tell this through static 2492 analysis of the rule, so implementations MUST be careful to avoid 2493 getting stuck in infinite loops, or otherwise exhausting resources 2494 while searching for the next occurrence. 2496 7.2. JSON Parsing 2498 The Security Considerations of [RFC8259] apply to the use of JSON as 2499 the data interchange format. 2501 As for any serialization format, parsers need to thoroughly check the 2502 syntax of the supplied data. JSON uses opening and closing tags for 2503 several types and structures, and it is possible that the end of the 2504 supplied data will be reached when scanning for a matching closing 2505 tag; this is an error condition, and implementations need to stop 2506 scanning at the end of the supplied data. 2508 JSON also uses a string encoding with some escape sequences to encode 2509 special characters within a string. Care is needed when processing 2510 these escape sequences to ensure that they are fully formed before 2511 the special processing is triggered, with special care taken when the 2512 escape sequences appear adjacent to other (non-escaped) special 2513 characters or adjacent to the end of data (as in the previous 2514 paragraph). 2516 If parsing JSON into a non-textual structured data format, 2517 implementations may need to allocate storage to hold JSON string 2518 elements. Since JSON does not use explicit string lengths, the risk 2519 of denial of service due to resource exhaustion is small, but 2520 implementations may still wish to place limits on the size of 2521 allocations they are willing to make in any given context, to avoid 2522 untrusted data causing excessive memory allocation. 2524 7.3. URI Values 2526 Several JSCalendar properties contain URIs as values, and processing 2527 these properties requires extra care. Section 7 of [RFC3986] 2528 discusses security risk related to URIs. 2530 8. IANA Considerations 2532 8.1. Media Type Registration 2534 This document defines a media type for use with JSCalendar data 2535 formatted in JSON. 2537 Type name: application 2539 Subtype name: jscalendar+json 2541 Required parameters: type 2543 The "type" parameter conveys the type of the JSCalendar data in 2544 the body part, with the value being one of "jsevent", "jstask", or 2545 "jsgroup". The parameter MUST NOT occur more than once. It MUST 2546 match the value of the "@type" property of the JSON-formatted 2547 JSCalendar object in the body. 2549 Optional parameters: none 2551 Encoding considerations: Same as encoding considerations of 2552 application/json as specified in RFC8529, Section 11 [RFC8259]. 2554 Security considerations: See Section 7 of this document. 2556 Interoperability considerations: This media type provides an 2557 alternative to iCalendar, jCal and proprietary JSON-based 2558 calendaring data formats. 2560 Published specification: This specification. 2562 Applications that use this media type: Applications that currently 2563 make use of the text/calendar and application/calendar+json media 2564 types can use this as an alternative. Similarly, applications 2565 that use the application/json media type to transfer calendaring 2566 data can use this to further specify the content. 2568 Fragment identifier considerations: N/A 2570 Additional information: 2572 Magic number(s): N/A 2574 File extensions(s): N/A 2576 Macintosh file type code(s): N/A 2578 Person & email address to contact for further information: 2579 calsify@ietf.org 2581 Intended usage: COMMON 2583 Restrictions on usage: N/A 2585 Author: See the "Author's Address" section of this document. 2587 Change controller: IETF 2589 8.2. Creation of "JSCalendar Properties" Registry 2591 The IANA will create the "JSCalendar Properties" registry to allow 2592 interoperability of extensions to JSCalendar objects. 2594 This registry follows the Expert Review process ([RFC8126], 2595 Section 4.5) unless the "intended use" field is "common", in which 2596 case registration follows the Specification Required process 2597 ([RFC8126], Section 4.6). Preliminary community review for this 2598 registry is optional but strongly encouraged. 2600 A registration can have an intended use of "common", "reserved", or 2601 "obsolete". The IANA will list common-use registrations prominently 2602 and separately from those with other intended use values. 2604 A "reserved" registration reserves a property name without assigning 2605 semantics to avoid name collisions with future extensions or protocol 2606 use. 2608 An "obsolete" registration denotes a property that is no longer 2609 expected to be added by up-to-date systems. A new property has 2610 probably been defined covering the obsolete property's semantics. 2612 The JSCalendar property registration procedure is not a formal 2613 standards process but rather an administrative procedure intended to 2614 allow community comment and sanity checking without excessive time 2615 delay. It is designed to encourage vendors to document and register 2616 new properties they add for use cases not covered by the original 2617 standard, leading to increased interoperability. 2619 8.2.1. Preliminary Community Review 2621 Notice of a potential new registration SHOULD be sent to the Calext 2622 mailing list for review. This mailing list is 2623 appropriate to solicit community feedback on a proposed new property. 2625 Properties registrations must be marked with their intended use: 2626 "common", "reserved" or "obsolete". 2628 The intent of the public posting to this list is to solicit comments 2629 and feedback on the choice of the property name, the unambiguity of 2630 the specification document, and a review of any interoperability or 2631 security considerations. The submitter may submit a revised 2632 registration proposal or abandon the registration completely at any 2633 time. 2635 8.2.2. Submit Request to IANA 2637 Registration requests can be sent to . 2639 8.2.3. Designated Expert Review 2641 The primary concern of the designated expert (DE) is preventing name 2642 collisions and encouraging the submitter to document security and 2643 privacy considerations. For a common-use registration, the DE is 2644 expected to confirm that suitable documentation, as described in 2645 Section 4.6 of [RFC8126], is available to ensure interoperability. 2646 This preferably takes the form of an RFC, but for simple definitions 2647 a description in the registry may be sufficient. The DE should also 2648 verify that the property name does not conflict with work that is 2649 active or already published within the IETF. A published 2650 specification is not required for reserved or obsolete registrations. 2652 The DE will either approve or deny the registration request and 2653 publish a notice of the decision to the Calext WG mailing list or its 2654 successor, as well as inform IANA. A denial notice must be justified 2655 by an explanation, and, in the cases where it is possible, concrete 2656 suggestions on how the request can be modified so as to become 2657 acceptable should be provided. 2659 8.2.4. Change Procedures 2661 Once a JSCalendar property has been published by the IANA, the change 2662 controller may request a change to its definition. The same 2663 procedure that would be appropriate for the original registration 2664 request is used to process a change request. 2666 JSCalendar property registrations may not be deleted; properties that 2667 are no longer believed appropriate for use can be declared obsolete 2668 by a change to their "intended use" field; such properties will be 2669 clearly marked in the lists published by the IANA. 2671 Significant changes to a JSCalendar property's definition should be 2672 requested only when there are serious omissions or errors in the 2673 published specification, as such changes may cause interoperability 2674 issues. When review is required, a change request may be denied if 2675 it renders entities that were valid under the previous definition 2676 invalid under the new definition. 2678 The owner of a JSCalendar property may pass responsibility to another 2679 person or agency by informing the IANA; this can be done without 2680 discussion or review. 2682 8.2.5. JMAP Properties Registry Template 2684 o Property Name: The name of the property. The property name MUST 2685 NOT already be registered for any of the object types listed in 2686 the "Property Context" field of this registration. Other object 2687 types MAY already have registered a different property with the 2688 same name. 2690 o Property Type: The type of this property, using type signatures as 2691 specified in Section 1.3. The property type MUST be registed in 2692 the Type Registry. 2694 o Property Context: A comma-separated list of JSCalendar object 2695 types this property is allowed on. 2697 o Reference or Description: A brief description or RFC number and 2698 section reference where the property is specified (omitted for 2699 "reserved" property names). 2701 o Intended Use: Common, reserved, or obsolete. 2703 o Change Controller: ("IETF" for IETF-stream RFCs). 2705 8.2.6. Initial Contents for the JSCalendar Properties Registry 2707 The following table lists the initial entries of the JSCalendar 2708 Properties registry. All properties are for common-use. All RFC 2709 section references are for this document. The change controller for 2710 all these properties is "IETF". 2712 +---------------+----------------------------+------------+---------+ 2713 | Property Name | Property Type | Property | Referen | 2714 | | | Context | ce or D | 2715 | | | | escript | 2716 | | | | ion | 2717 +---------------+----------------------------+------------+---------+ 2718 | @type | String | JSEvent, | Section | 2719 | | | JSTask, | 4.1.1, | 2720 | | | JSGroup, A | Section | 2721 | | | bsoluteTri | 4.5.2, | 2722 | | | gger, | Section | 2723 | | | Alert, | 4.2.7, | 2724 | | | Link, | Section | 2725 | | | Location, | 4.2.5, | 2726 | | | OffsetTrig | Section | 2727 | | | ger, Parti | 4.4.5, | 2728 | | | cipant, Re | Section | 2729 | | | currenceRu | 4.3.2, | 2730 | | | le, | Section | 2731 | | | Relation, | 4.1.3, | 2732 | | | TimeZone, | Section | 2733 | | | VirtualLoc | 4.7.2, | 2734 | | | ation | Section | 2735 | | | | 4.2.6 | 2736 | | | | | 2737 | acknowledged | UTCDateTime | Alert | Section | 2738 | | | | 4.5.2 | 2739 | | | | | 2740 | action | String | Alert | Section | 2741 | | | | 4.5.2 | 2742 | | | | | 2743 | alerts | Id[Alert] | JSEvent, | Section | 2744 | | | JSTask | 4.5.2 | 2745 | | | | | 2746 | byDay | NDay[] | Recurrence | Section | 2747 | | | Rule | 4.3.2 | 2748 | | | | | 2749 | byHour | UnsignedInt[] | Recurrence | Section | 2750 | | | Rule | 4.3.2 | 2751 | | | | | 2752 | byMinute | UnsignedInt[] | Recurrence | Section | 2753 | | | Rule | 4.3.2 | 2754 | | | | | 2755 | byMonth | String[] | Recurrence | Section | 2756 | | | Rule | 4.3.2 | 2757 | | | | | 2758 | byMonthDay | Int[] | Recurrence | Section | 2759 | | | Rule | 4.3.2 | 2760 | | | | | 2761 | bySecond | UnsignedInt[] | Recurrence | Section | 2762 | | | Rule | 4.3.2 | 2763 | | | | | 2764 | bySetPosition | Int[] | Recurrence | Section | 2765 | | | Rule | 4.3.2 | 2766 | | | | | 2767 | byWeekNo | Int[] | Recurrence | Section | 2768 | | | Rule | 4.3.2 | 2769 | | | | | 2770 | byYearDay | Int[] | Recurrence | Section | 2771 | | | Rule | 4.3.2 | 2772 | | | | | 2773 | categories | String[Boolean] | JSEvent, | Section | 2774 | | | JSTask, | 4.2.10 | 2775 | | | JSGroup | | 2776 | | | | | 2777 | cid | String | Link | Section | 2778 | | | | 4.2.7 | 2779 | | | | | 2780 | color | String | JSEvent, | Section | 2781 | | | JSTask, | 4.2.11 | 2782 | | | JSGroup | | 2783 | | | | | 2784 | contentType | String | Link | Section | 2785 | | | | 4.2.7 | 2786 | | | | | 2787 | coordinates | String | Location | Section | 2788 | | | | 4.2.5 | 2789 | | | | | 2790 | count | UnsignedInt | Recurrence | Section | 2791 | | | Rule | 4.3.2 | 2792 | | | | | 2793 | created | UTCDateTime | JSEvent, | Section | 2794 | | | JSTask, | 4.1.5 | 2795 | | | JSGroup | | 2796 | | | | | 2797 | delegatedFrom | String[Boolean] | Participan | Section | 2798 | | | t | 4.4.5 | 2799 | | | | | 2800 | delegatedTo | String[Boolean] | Participan | Section | 2801 | | | t | 4.4.5 | 2802 | | | | | 2803 | description | String | JSEvent, | Section | 2804 | | | JSTask, | 4.2.2, | 2805 | | | Location, | Section | 2806 | | | VirtualLoc | 4.2.5, | 2807 | | | ation | Section | 2808 | | | | 4.2.6 | 2809 | | | | | 2810 | descriptionCo | String | JSEvent, | Section | 2811 | ntentType | | JSTask | 4.2.3 | 2812 | | | | | 2813 | display | String | Link | Section | 2814 | | | | 4.2.7 | 2815 | | | | | 2816 | due | LocalDateTime | JSTask | Section | 2817 | | | | 5.2.1 | 2818 | | | | | 2819 | duration | Duration | JSEvent | Section | 2820 | | | | 5.1.2 | 2821 | | | | | 2822 | email | String | Participan | Section | 2823 | | | t | 4.4.5 | 2824 | | | | | 2825 | entries | String[JSTask|JSEvent] | JSGroup | Section | 2826 | | | | 5.3.1 | 2827 | | | | | 2828 | estimatedDura | Duration | JSTask | Section | 2829 | tion | | | 5.2.3 | 2830 | | | | | 2831 | excluded | Boolean | JSEvent, | Section | 2832 | | | JSTask | 4.3.4 | 2833 | | | | | 2834 | expectReply | Boolean | Participan | Section | 2835 | | | t | 4.4.5 | 2836 | | | | | 2837 | firstDayOfWee | String | Recurrence | Section | 2838 | k | | Rule | 4.3.2 | 2839 | | | | | 2840 | freeBusyStatu | String | JSEvent, | Section | 2841 | s | | JSTask | 4.4.2 | 2842 | | | | | 2843 | frequency | String | Recurrence | Section | 2844 | | | Rule | 4.3.2 | 2845 | | | | | 2846 | href | String | Link | Section | 2847 | | | | 4.2.7 | 2848 | | | | | 2849 | interval | UnsignedInt | Recurrence | Section | 2850 | | | Rule | 4.3.2 | 2851 | | | | | 2852 | invitedBy | String | Participan | Section | 2853 | | | t | 4.4.5 | 2854 | | | | | 2855 | keywords | String[Boolean] | JSEvent, | Section | 2856 | | | JSTask, | 4.2.9 | 2857 | | | JSGroup | | 2858 | | | | | 2859 | kind | String | Participan | Section | 2860 | | | t | 4.4.5 | 2861 | | | | | 2862 | language | String | Participan | Section | 2863 | | | t | 4.4.5 | 2864 | | | | | 2865 | linkIds | Id[Boolean] | Location, | Section | 2866 | | | Participan | 4.2.5, | 2867 | | | t | Section | 2868 | | | | 4.4.5 | 2869 | | | | | 2870 | links | Id[Link] | JSGroup, | Section | 2871 | | | JSEvent, | 4.2.7 | 2872 | | | JSTask | | 2873 | | | | | 2874 | locale | String | JSGroup, | Section | 2875 | | | JSEvent, | 4.2.7 | 2876 | | | JSTask | | 2877 | | | | | 2878 | localizations | String[PatchObject] | JSEvent, | Section | 2879 | | | JSTask | 4.6.1 | 2880 | | | | | 2881 | locationId | String | Participan | Section | 2882 | | | t | 4.4.5 | 2883 | | | | | 2884 | locations | Id[Location] | JSEvent, | Section | 2885 | | | JSTask | 4.2.5 | 2886 | | | | | 2887 | locationTypes | String[Boolean] | Location | Section | 2888 | | | | 4.2.5 | 2889 | | | | | 2890 | memberOf | String[Boolean] | Participan | Section | 2891 | | | t | 4.4.5 | 2892 | | | | | 2893 | method | String | JSEvent, | Section | 2894 | | | JSTask | 4.1.8 | 2895 | | | | | 2896 | name | String | Location, | Section | 2897 | | | VirtualLoc | 4.2.5, | 2898 | | | ation, Par | Section | 2899 | | | ticipant | 4.2.6, | 2900 | | | | Section | 2901 | | | | 4.4.5 | 2902 | | | | | 2903 | offset | SignedDuration | OffsetTrig | Section | 2904 | | | ger | 4.5.2 | 2905 | | | | | 2906 | participants | Id[Participant] | JSEvent, | Section | 2907 | | | JSTask | 4.4.5 | 2908 | | | | | 2909 | participation | String | Participan | Section | 2910 | Comment | | t | 4.4.5 | 2911 | | | | | 2912 | participation | String | Participan | Section | 2913 | Status | | t | 4.4.5 | 2914 | | | | | 2915 | priority | Int | JSEvent, | Section | 2916 | | | JSTask | 4.4.1 | 2917 | | | | | 2918 | privacy | String | JSEvent, | Section | 2919 | | | JSTask | 4.4.3 | 2920 | | | | | 2921 | prodId | String | JSEvent, | Section | 2922 | | | JSTask, | 4.1.4 | 2923 | | | JSGroup | | 2924 | | | | | 2925 | progress | String | JSTask, Pa | Section | 2926 | | | rticipant | 5.2.4 | 2927 | | | | | 2928 | progressUpdat | UTCDateTime | JSTask, Pa | Section | 2929 | ed | | rticipant | 5.2.5 | 2930 | | | | | 2931 | recurrenceId | LocalDateTime | JSEvent, | Section | 2932 | | | JSTask | 4.3.1 | 2933 | | | | | 2934 | recurrenceOve | LocalDateTime[PatchObject] | JSEvent, | Section | 2935 | rrides | | JSTask | 4.3.3 | 2936 | | | | | 2937 | recurrenceRul | RecurrenceRule[] | JSEvent, | Section | 2938 | es | | JSTask | 4.3.2 | 2939 | | | | | 2940 | rel | String | Link | Section | 2941 | | | | 4.2.7 | 2942 | | | | | 2943 | relatedTo | String[Relation] | JSEvent, | Section | 2944 | | | JSTask, | 4.1.3, | 2945 | | | Alert | Section | 2946 | | | | 4.5.2 | 2947 | | | | | 2948 | relation | String[Boolean] | Relation | Section | 2949 | | | | 1.4.10 | 2950 | | | | | 2951 | relativeTo | String | OffsetTrig | Section | 2952 | | | ger, | 4.5.2, | 2953 | | | Location | Section | 2954 | | | | 4.2.5 | 2955 | | | | | 2956 | replyTo | String[String] | JSEvent, | Section | 2957 | | | JSTask | 4.4.4 | 2958 | | | | | 2959 | roles | String[Boolean] | Participan | Section | 2960 | | | t | 4.4.5 | 2961 | | | | | 2962 | rscale | String | Recurrence | Section | 2963 | | | Rule | 4.3.2 | 2964 | | | | | 2965 | scheduleAgent | String | Participan | Section | 2966 | | | t | 4.4.5 | 2967 | | | | | 2968 | scheduleSeque | UnsignedInt | Participan | Section | 2969 | nce | | t | 4.4.5 | 2970 | | | | | 2971 | scheduleUpdat | UTCDateTime | Participan | Section | 2972 | ed | | t | 4.4.5 | 2973 | | | | | 2974 | sendTo | String[String] | Participan | Section | 2975 | | | t | 4.4.5 | 2976 | | | | | 2977 | sequence | UnsignedInt | JSEvent, | Section | 2978 | | | JSTask | 4.1.7 | 2979 | | | | | 2980 | showWithoutTi | Boolean | JSEvent, | Section | 2981 | me | | JSTask | 4.2.4 | 2982 | | | | | 2983 | size | UnsignedInt | Link | Section | 2984 | | | | 4.2.7 | 2985 | | | | | 2986 | skip | String | Recurrence | Section | 2987 | | | Rule | 4.3.2 | 2988 | | | | | 2989 | source | String | JSGroup | Section | 2990 | | | | 5.3.2 | 2991 | | | | | 2992 | start | LocalDateTime | JSEvent, | Section | 2993 | | | JSTask | 5.1.1, | 2994 | | | | Section | 2995 | | | | 5.2.2 | 2996 | | | | | 2997 | status | String | JSEvent | Section | 2998 | | | | 5.1.3 | 2999 | | | | | 3000 | timeZone | String|null | JSEvent, | Section | 3001 | | | JSTask, | 4.7.1, | 3002 | | | Location | Section | 3003 | | | | 4.2.5 | 3004 | | | | | 3005 | timeZones | String[TimeZone] | JSEvent, | Section | 3006 | | | JSTask | 4.7.2 | 3007 | | | | | 3008 | title | String | JSEvent, | Section | 3009 | | | JSTask, | 4.2.1 | 3010 | | | JSGroup, | | 3011 | | | Link | | 3012 | | | | | 3013 | trigger | OffsetTrigger|AbsoluteTrig | Alert | Section | 3014 | | ger|UnknownTrigger | | 4.5.2 | 3015 | | | | | 3016 | uid | String | JSEvent, | Section | 3017 | | | JSTask, | 4.1.2 | 3018 | | | JSGroup | | 3019 | | | | | 3020 | until | LocalDateTime | Recurrence | Section | 3021 | | | Rule | 4.3.2 | 3022 | | | | | 3023 | updated | UTCDateTime | JSEvent, | Section | 3024 | | | JSTask, | 4.1.6 | 3025 | | | JSGroup | | 3026 | | | | | 3027 | uri | String | VirtualLoc | Section | 3028 | | | ation | 4.2.6 | 3029 | | | | | 3030 | useDefaultAle | Boolean | JSEvent, | Section | 3031 | rts | | JSTask | 4.5.1 | 3032 | | | | | 3033 | virtualLocati | Id[VirtualLocation] | JSEvent, | Section | 3034 | ons | | JSTask | 4.2.6 | 3035 | | | | | 3036 | when | UTCDateTime | AbsoluteTr | Section | 3037 | | | igger | 4.5.2 | 3038 +---------------+----------------------------+------------+---------+ 3040 Table 1 3042 8.3. Creation of "JSCalendar Types" Registry 3044 The IANA will create the "JSCalendar Types" registry to avoid name 3045 collisions and provide a complete reference for all data types used 3046 for JSCalendar property values. The registration process is the same 3047 as for the JSCalendar Properties registry, as defined in Section 8.2. 3049 8.3.1. JMAP Types Registry Template 3051 o Type Name: The name of the type. 3053 o Reference or Description: A brief description or RFC number and 3054 section reference where the Type is specified (may be omitted for 3055 "reserved" type names). 3057 o Intended Use: Common, reserved, or obsolete. 3059 o Change Controller: ("IETF" for IETF-stream RFCs). 3061 8.3.2. Initial Contents for the JSCalendar Types Registry 3063 The following table lists the initial entries of the JSCalendar Types 3064 registry. All properties are for common-use. All RFC section 3065 references are for this document. The change controller for all 3066 these properties is "IETF". 3068 +-----------------+--------------------------+ 3069 | Type Name | Reference or Description | 3070 +-----------------+--------------------------+ 3071 | Alert | Section 4.5.2 | 3072 | | | 3073 | Boolean | Section 1.3 | 3074 | | | 3075 | Duration | Section 1.4.5 | 3076 | | | 3077 | Id | Section 1.4.7 | 3078 | | | 3079 | Int | Section 1.4.1 | 3080 | | | 3081 | LocalDateTime | Section 1.4.4 | 3082 | | | 3083 | Link | Section 4.2.7 | 3084 | | | 3085 | Location | Section 4.2.5 | 3086 | | | 3087 | Number | Section 1.3 | 3088 | | | 3089 | Participant | Section 4.4.5 | 3090 | | | 3091 | PatchObject | Section 1.4.8 | 3092 | | | 3093 | RecurrenceRule | Section 4.3.2 | 3094 | | | 3095 | Relation | Section 1.4.10 | 3096 | | | 3097 | SignedDuration | Section 1.4.6 | 3098 | | | 3099 | String | Section 1.3 | 3100 | | | 3101 | TimeZone | Section 4.7.2 | 3102 | | | 3103 | TimeZoneRule | Section 4.7.2 | 3104 | | | 3105 | UnsignedInt | Section 1.4.2 | 3106 | | | 3107 | UTCDateTime | Section 1.4.3 | 3108 | | | 3109 | VirtualLocation | Section 4.2.6 | 3110 +-----------------+--------------------------+ 3112 Table 2 3114 8.4. Creation of "JSCalendar Enum Values" Registry 3116 The IANA will create the "JSCalendar Enum Values" registry to allow 3117 interoperable extension of semantics for properties with enumerable 3118 values. Each such property will have a subregistry of allowed 3119 values. The registration process for creating a new subregistry is 3120 the same as for the JSCalendar Properties registry. The registration 3121 process for a new enum value is the same but is only subject to 3122 Expert Review; a specification is not required for a new allowed 3123 value in an existing enum property where a simple description will 3124 suffice. 3126 8.4.1. JMAP Enum Subregistry Creation Template 3128 This template is for adding a new subregistry to the JMAP Enum 3129 registry. 3131 o Registry Name: This MUST be of the form "Enum Values for 3132 {property-name} (Context: {context})" where: 3134 {property-name} is the name(s) of the property or properties where 3135 these values may be used. This MUST be registered in the 3136 JSCalendar Properties registry. 3138 {context} is the list of allowed object types where the property 3139 or properties may appear, as registered in the JSCalendar 3140 Properties registry. This disambiguates where there may be two 3141 distinct properties with the same name in different contexts. 3143 o Change Controller: ("IETF" for IETF-stream RFCs). 3145 o Experts: The initial list of experts for Expert Review of updates 3146 to the subregistry. 3148 o Initial Contents: The initial list of defined values for this 3149 enum, using the template defined in Section 8.4.2. 3151 8.4.2. JMAP Enum Subregistry Template 3153 This template is for adding a new enum value to a subregistry in the 3154 JMAP Enum registry. 3156 o Enum Value: The verbatim value of the enum. 3158 o Reference or Description: A brief description or RFC number and 3159 section reference for the semantics of this value. 3161 8.4.3. Initial Contents for the JSCalendar Enum Registry 3163 For each subregistry created in this section, all RFC section 3164 references are for this document, the change controller is IETF and 3165 the experts are Neil Jenkins and Robert Stepanek. 3167 ------------------------------------------------------------ 3169 Enum Values for action (Context: Alert) 3171 +------------+--------------------------+ 3172 | Enum Value | Reference or Description | 3173 +------------+--------------------------+ 3174 | display | Section 4.5.2 | 3175 | | | 3176 | email | Section 4.5.2 | 3177 +------------+--------------------------+ 3179 Table 3 3181 ------------------------------------------------------------ 3183 Enum Values for display (Context: Link) 3185 +------------+--------------------------+ 3186 | Enum Value | Reference or Description | 3187 +------------+--------------------------+ 3188 | badge | Section 4.2.7 | 3189 | | | 3190 | graphic | Section 4.2.7 | 3191 | | | 3192 | fullsize | Section 4.2.7 | 3193 | | | 3194 | thumbnail | Section 4.2.7 | 3195 +------------+--------------------------+ 3197 Table 4 3199 ------------------------------------------------------------ 3201 Enum Values for freeBusyStatus (Context: JSEvent, JSTask) 3202 +------------+--------------------------+ 3203 | Enum Value | Reference or Description | 3204 +------------+--------------------------+ 3205 | free | Section 4.4.2 | 3206 | | | 3207 | busy | Section 4.4.2 | 3208 +------------+--------------------------+ 3210 Table 5 3212 ------------------------------------------------------------ 3214 Enum Values for kind (Context: Participant) 3216 +------------+--------------------------+ 3217 | Enum Value | Reference or Description | 3218 +------------+--------------------------+ 3219 | individual | Section 4.4.5 | 3220 | | | 3221 | group | Section 4.4.5 | 3222 | | | 3223 | resource | Section 4.4.5 | 3224 | | | 3225 | location | Section 4.4.5 | 3226 +------------+--------------------------+ 3228 Table 6 3230 ------------------------------------------------------------ 3232 Enum Values for participationStatus (Context: Participant) 3234 +--------------+--------------------------+ 3235 | Enum Value | Reference or Description | 3236 +--------------+--------------------------+ 3237 | needs-action | Section 4.4.5 | 3238 | | | 3239 | accepted | Section 4.4.5 | 3240 | | | 3241 | declined | Section 4.4.5 | 3242 | | | 3243 | tenative | Section 4.4.5 | 3244 | | | 3245 | delegated | Section 4.4.5 | 3246 +--------------+--------------------------+ 3248 Table 7 3250 ------------------------------------------------------------ 3252 Enum Values for privacy (Context: JSEvent, JSTask) 3254 +------------+--------------------------+ 3255 | Enum Value | Reference or Description | 3256 +------------+--------------------------+ 3257 | public | Section 4.4.3 | 3258 | | | 3259 | private | Section 4.4.3 | 3260 | | | 3261 | secret | Section 4.4.3 | 3262 +------------+--------------------------+ 3264 Table 8 3266 ------------------------------------------------------------ 3268 Enum Values for progress (Context: JSTask, Participant) 3270 +--------------+--------------------------+ 3271 | Enum Value | Reference or Description | 3272 +--------------+--------------------------+ 3273 | needs-action | Section 5.2.4 | 3274 | | | 3275 | in-process | Section 5.2.4 | 3276 | | | 3277 | completed | Section 5.2.4 | 3278 | | | 3279 | failed | Section 5.2.4 | 3280 | | | 3281 | cancelled | Section 5.2.4 | 3282 +--------------+--------------------------+ 3284 Table 9 3286 ------------------------------------------------------------ 3288 Enum Values for relation (Context: Relation) 3289 +------------+--------------------------+ 3290 | Enum Value | Reference or Description | 3291 +------------+--------------------------+ 3292 | first | Section 1.4.10 | 3293 | | | 3294 | next | Section 1.4.10 | 3295 | | | 3296 | child | Section 1.4.10 | 3297 | | | 3298 | parent | Section 1.4.10 | 3299 +------------+--------------------------+ 3301 Table 10 3303 ------------------------------------------------------------ 3305 Enum Values for relativeTo (Context: OffsetTrigger, Location) 3307 +------------+--------------------------+ 3308 | Enum Value | Reference or Description | 3309 +------------+--------------------------+ 3310 | start | Section 4.5.2 | 3311 | | | 3312 | end | Section 4.5.2 | 3313 +------------+--------------------------+ 3315 Table 11 3317 ------------------------------------------------------------ 3319 Enum Values for roles (Context: Participant) 3321 +---------------+--------------------------+ 3322 | Enum Value | Reference or Description | 3323 +---------------+--------------------------+ 3324 | owner | Section 4.4.5 | 3325 | | | 3326 | attendee | Section 4.4.5 | 3327 | | | 3328 | optional | Section 4.4.5 | 3329 | | | 3330 | informational | Section 4.4.5 | 3331 | | | 3332 | chair | Section 4.4.5 | 3333 +---------------+--------------------------+ 3335 Table 12 3337 ------------------------------------------------------------ 3339 Enum Values for scheduleAgent (Context: Participant) 3341 +------------+--------------------------+ 3342 | Enum Value | Reference or Description | 3343 +------------+--------------------------+ 3344 | server | Section 4.4.5 | 3345 | | | 3346 | client | Section 4.4.5 | 3347 | | | 3348 | none | Section 4.4.5 | 3349 +------------+--------------------------+ 3351 Table 13 3353 ------------------------------------------------------------ 3355 Enum Values for status (Context: JSEvent) 3357 +------------+--------------------------+ 3358 | Enum Value | Reference or Description | 3359 +------------+--------------------------+ 3360 | confirmed | Section 5.1.3 | 3361 | | | 3362 | cancelled | Section 5.1.3 | 3363 | | | 3364 | tentative | Section 5.1.3 | 3365 +------------+--------------------------+ 3367 Table 14 3369 9. Acknowledgments 3371 The authors would like to thank the members of CalConnect for their 3372 valuable contributions. This specification originated from the work 3373 of the API technical committee of CalConnect, the Calendaring and 3374 Scheduling Consortium. 3376 10. References 3378 10.1. Normative References 3380 [CLDR] "Unicode Common Locale Data Repository", 3381 . 3383 [COLORS] "CSS Color Module", . 3385 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 3386 Requirement Levels", BCP 14, RFC 2119, 3387 DOI 10.17487/RFC2119, March 1997, 3388 . 3390 [RFC2392] Levinson, E., "Content-ID and Message-ID Uniform Resource 3391 Locators", RFC 2392, DOI 10.17487/RFC2392, August 1998, 3392 . 3394 [RFC2397] Masinter, L., "The "data" URL scheme", RFC 2397, 3395 DOI 10.17487/RFC2397, August 1998, 3396 . 3398 [RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet: 3399 Timestamps", RFC 3339, DOI 10.17487/RFC3339, July 2002, 3400 . 3402 [RFC4589] Schulzrinne, H. and H. Tschofenig, "Location Types 3403 Registry", RFC 4589, DOI 10.17487/RFC4589, July 2006, 3404 . 3406 [RFC4648] Josefsson, S., "The Base16, Base32, and Base64 Data 3407 Encodings", RFC 4648, DOI 10.17487/RFC4648, October 2006, 3408 . 3410 [RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and 3411 Scheduling Core Object Specification (iCalendar)", 3412 RFC 5545, DOI 10.17487/RFC5545, September 2009, 3413 . 3415 [RFC5646] Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying 3416 Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646, 3417 September 2009, . 3419 [RFC5870] Mayrhofer, A. and C. Spanring, "A Uniform Resource 3420 Identifier for Geographic Locations ('geo' URI)", 3421 RFC 5870, DOI 10.17487/RFC5870, June 2010, 3422 . 3424 [RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type 3425 Specifications and Registration Procedures", BCP 13, 3426 RFC 6838, DOI 10.17487/RFC6838, January 2013, 3427 . 3429 [RFC6901] Bryan, P., Ed., Zyp, K., and M. Nottingham, Ed., 3430 "JavaScript Object Notation (JSON) Pointer", RFC 6901, 3431 DOI 10.17487/RFC6901, April 2013, 3432 . 3434 [RFC7493] Bray, T., Ed., "The I-JSON Message Format", RFC 7493, 3435 DOI 10.17487/RFC7493, March 2015, 3436 . 3438 [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for 3439 Writing an IANA Considerations Section in RFCs", BCP 26, 3440 RFC 8126, DOI 10.17487/RFC8126, June 2017, 3441 . 3443 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 3444 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 3445 May 2017, . 3447 [RFC8259] Bray, T., Ed., "The JavaScript Object Notation (JSON) Data 3448 Interchange Format", STD 90, RFC 8259, 3449 DOI 10.17487/RFC8259, December 2017, 3450 . 3452 [RFC8288] Nottingham, M., "Web Linking", RFC 8288, 3453 DOI 10.17487/RFC8288, October 2017, 3454 . 3456 [TZDB] "IANA Time Zone Database", 3457 . 3459 10.2. Informative References 3461 [LINKRELS] 3462 "IANA Link Relation Types", 3463 . 3466 [MIME] "IANA Media Types", . 3469 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 3470 Resource Identifier (URI): Generic Syntax", STD 66, 3471 RFC 3986, DOI 10.17487/RFC3986, January 2005, 3472 . 3474 [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally 3475 Unique IDentifier (UUID) URN Namespace", RFC 4122, 3476 DOI 10.17487/RFC4122, July 2005, 3477 . 3479 [RFC4791] Daboo, C., Desruisseaux, B., and L. Dusseault, 3480 "Calendaring Extensions to WebDAV (CalDAV)", RFC 4791, 3481 DOI 10.17487/RFC4791, March 2007, 3482 . 3484 [RFC5546] Daboo, C., Ed., "iCalendar Transport-Independent 3485 Interoperability Protocol (iTIP)", RFC 5546, 3486 DOI 10.17487/RFC5546, December 2009, 3487 . 3489 [RFC6047] Melnikov, A., Ed., "iCalendar Message-Based 3490 Interoperability Protocol (iMIP)", RFC 6047, 3491 DOI 10.17487/RFC6047, December 2010, 3492 . 3494 [RFC7265] Kewisch, P., Daboo, C., and M. Douglass, "jCal: The JSON 3495 Format for iCalendar", RFC 7265, DOI 10.17487/RFC7265, May 3496 2014, . 3498 [RFC7529] Daboo, C. and G. Yakushev, "Non-Gregorian Recurrence Rules 3499 in the Internet Calendaring and Scheduling Core Object 3500 Specification (iCalendar)", RFC 7529, 3501 DOI 10.17487/RFC7529, May 2015, 3502 . 3504 [RFC7808] Douglass, M. and C. Daboo, "Time Zone Data Distribution 3505 Service", RFC 7808, DOI 10.17487/RFC7808, March 2016, 3506 . 3508 [RFC7986] Daboo, C., "New Properties for iCalendar", RFC 7986, 3509 DOI 10.17487/RFC7986, October 2016, 3510 . 3512 Authors' Addresses 3514 Neil Jenkins 3515 Fastmail 3516 PO Box 234 3517 Collins St West 3518 Melbourne VIC 8007 3519 Australia 3521 Email: neilj@fastmailteam.com 3522 URI: https://www.fastmail.com 3523 Robert Stepanek 3524 Fastmail 3525 PO Box 234 3526 Collins St West 3527 Melbourne VIC 8007 3528 Australia 3530 Email: rsto@fastmailteam.com 3531 URI: https://www.fastmail.com