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CalConnect Standards, Specifications, Reports, Amendments, and Technical Corrigenda — formally approved deliverables defining normative requirements and technical protocols for calendar and scheduling interoperability.

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CC/WD 51020:2019 Working-draft
standard Ed. 1 2026-05-13
Collection Query Report for Web Distributed Authoring and Versioning (WebDAV)

Kenneth Murchison, Michael Douglass (CALENDAR)

<p>This specification defines an extension to Web Distributed Authoring and Versioning (WebDAV) to search for WebDAV collections based upon a set of client-supplied criteria.</p>

CC/WD 51017:2024-07-23 Working-draft
standard Ed. 1 2026-05-13
VALARM Extensions for iCalendar

Cyrus Daboo, Kenneth Murchison (CALENDAR)

<p>This document defines a set of extensions to the iCalendar VALARM component to enhance use of alarms and improve interoperability between clients and servers.</p>

CC 11001:2024 Standard
standard Ed. 0 2026-05-13
Calendaring — Task Extensions to iCalendar

Adrian Apthorp, Michael Douglass (CALENDAR)

<p>The Internet Calendaring and Scheduling Core Object Specification (iCalendar) (RFC5545) VTODO calendar component has seen limited adoption and use, mainly for personal reminders and to-do lists.</p> <p>This document updates and defines extensions to VTODO to provide improved status tracking, scheduling and specification of tasks to allow its use in other contexts, such as process control and project management.</p> <p>It also defines how Calendaring Extensions to WebDAV (CalDAV) (RFC 4791) servers can be extended to support certain automated task management behaviours.</p> <p>The Calendaring and Scheduling Consortium ("<tt>CalConnect</tt>") is a global non-profit organization with the aim to facilitate interoperability of collaborative technologies and tools through open standards.</p> <p>CalConnect works closely with international and regional partners, of which the full list is available on our website (<link target="https://www.calconnect.org/about/liaisons-and-relationships"/>).</p> <p>The procedures used to develop this document and those intended for its further maintenance are described in the CalConnect Directives.</p> <p>In particular the different approval criteria needed for the different types of CalConnect documents should be noted. This document was drafted in accordance with the editorial rules of the CalConnect Directives.</p> <p>Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CalConnect shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be provided in the Introduction.</p> <p>Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.</p> <p>This document was prepared by Technical Committee <em>CALENDAR</em>.</p>

CC/CD 51011:2024 Committee-draft
standard Ed. 1 2024-12-01
CC/CD 51006:2024 Committee-draft
standard Ed. 1 2024-04-22
CC 51008:2024 Published
standard Ed. 1 2022-06-27
Calendar and scheduling — iCalendar Transport-Independent Interoperability Protocol (iTIP)

Michael Douglass (CALENDAR)

<p>This document specifies a protocol that uses calendar objects to provide scheduling interoperability between different calendaring systems. This is done without reference to a specific transport protocol so as to allow multiple methods of communication between systems. Other documents define profiles of this protocol that use specific, interoperable methods of communication between systems.</p> <p>The iCalendar Transport-Independent Interoperability Protocol (iTIP) complements the calendar object specifications by adding semantics for group scheduling methods commonly available in current calendaring systems. These scheduling methods permit two or more calendaring systems to perform transactions such as publishing, scheduling, rescheduling, responding to scheduling requests, negotiating changes, or canceling.</p>

CC/WD 51023:2022 Working-draft
standard Ed. 1 2022-05-18
Serverside Subscriptions

Michael Douglass (CALENDAR)

<p>This specification provides a mechanism whereby subscriptions to external resources can be handled by the server.</p> <p>This specification updates <eref type="inline" bibitemid="RFC4791" citeas="IETF RFC 4791"/> to add new properties for the MKCOL request.</p>

CC/WD 24229:2022 Working-draft
standard Ed. 1 2022-05-16
CC/WD 56010:2019 Working-draft
standard Ed. 1 2021-04-15
vObject — Internationalization

Ronald Tse, Jeffrey Lau, Mike Douglass (VCARD)

CC/WD 51021:2021 Working-draft
standard Ed. 1 2021-03-26
Event Publishing Extensions to iCalendar

Michael Douglass (CALENDAR)

<p>This specification updates <eref type="inline" bibitemid="RFC5545" citeas="IETF RFC 5545"/> by introducing a number of new iCalendar properties and components which are of particular use for event publishers and in social networking.</p> <p>This specification also defines a new STRUCTURED-DATA property for iCalendar <eref type="inline" bibitemid="RFC5545" citeas="IETF RFC 5545"/> to allow for data that is directly pertinent to an event or task to be included with the calendar data.</p>

CC/R 18003:2019 Published
report Ed. 1 2019-01-18
Calendar operator practices — Guidelines to protect against calendar abuse

Thomas Schäfer, 1&1 Mail&Media Development and Technology GmbH, Jesse Thompson, University of Wisconsin-Madison (CALSPAM)

CC/WD 51013:2019 Working-draft
standard Ed. 1 2019-01-01
CalDAV Managed Attachments

Cyrus Daboo, Arnaud Quillaud, Kenneth Murchison (CALENDAR)

<p>This specification defines an extension to the calendar access protocol (CalDAV) to allow attachments associated with iCalendar data to be stored and managed on the server.</p> <p>This specification documents existing code deployed by multiple vendors. It is published as an Informational specification rather than Standards Track due to its noncompliance with multiple best current practices of HTTP.</p>

CC/CD 51003:2018 Committee-draft
standard Ed. 1 2018-11-30
CC/CD 51004:2018 Committee-draft
standard Ed. 1 2018-11-30
CC/WD 51016:2018 Working-draft
standard Ed. 1 2018-08-01
Streaming Calendar and Contacts Data

Michael Douglass (CALENDAR)

<p>This specification defines a model for streaming calendar and contact data. This allows for a more efficient method for synchronizing collections of data and may be used to augment existing protocols such as CalDAV.</p>

CC/CD 51016:2018 Committee-draft
standard Ed. 1 2018-02-21
Calendaring and scheduling — CalDAV Auditing Status and Feedback

Cyrus Daboo (CALENDAR)

<p>This document defines an extension to CalDAV that allows clients and servers that audit data on the server, to provide feedback based on the results of such audits. This can be used to signal clients about junk events, or other inappropriate content. It can also be used by clients to provide feedback about junk events, or other inappropriate content, that the server can act on in a manner that prevents the originator of the data from knowing it was discarded.</p>

CC/WD 51019:2018 Working-draft
standard Ed. 1 2018-02-03
Resources for Developing Calendar Applications

Kenneth Murchison (CALENDAR)

<p>This memo lists specifications and resources available to developers of calendaring and scheduling applications.</p>

CC/CD 70025:2017 Committee-draft
standard Ed. 1 2017-04-17
Calendaring and scheduling — Push Discovery and Notification Dispatch Protocol

Marten Gajda (PUSH)

<p>This specification defines a framework and protocols for a push notification system that allows clients, application servers and push notification servers to interact with each other in a standardized manner.</p> <p>The Calendaring and Scheduling Consortium ("<tt>CalConnect</tt>") is a global non-profit organization with the aim to facilitate interoperability of collaborative technologies and tools through open standards.</p> <p>CalConnect works closely with international and regional partners, of which the full list is available on our website (<link target="https://www.calconnect.org/about/liaisons-and-relationships"/>).</p> <p>The procedures used to develop this document and those intended for its further maintenance are described in the CalConnect Directives.</p> <p>In particular the different approval criteria needed for the different types of CalConnect documents should be noted. This document was drafted in accordance with the editorial rules of the CalConnect Directives.</p> <p>Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CalConnect shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be provided in the Introduction.</p> <p>Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.</p> <p>This document was prepared by Technical Committee <em>PUSH</em>.</p>

CC/WD 51012:2017 Working-draft
standard Ed. 1 2017-02-12
Enhanced Synchronization for Calendaring Extensions to WebDAV (CalDAV)

Cyrus Daboo, Kenneth Murchison (CALENDAR)

<p>This document defines new protocol features for CalDAV (<eref type="inline" bibitemid="RFC4791" citeas="IETF RFC 4791"/>) to improve the efficiency of synchronizing data changes between a client and server.</p>

CC/WD 51010:2017 Working-draft
standard Ed. 1 2017-01-01
Internet Calendar Scheduling Protocol (iSchedule)

Cyrus Daboo, Bernard Desruisseaux, Kenneth Murchison (CALENDAR)

<p>This document defines the Internet Calendar Scheduling Protocol (iSchedule), which is a binding from the iCalendar Transport-independent Interoperability Protocol (iTIP) to the Hypertext Transfer Protocol (HTTP) to enable interoperability between calendaring and scheduling systems over the Internet.</p>

CC/WD 51012:2016 Working-draft
standard Ed. 1 2016-10-28
vObject — vObject Model and vFormat Syntax

Cyrus Daboo, Kenneth Murchison (CALENDAR)

CC/WD 51014:2016 Working-draft
standard Ed. 1 2016-10-28
The iCalendar VINSTANCE Component

Cyrus Daboo (CALENDAR)

<p>This document updates the iCalendar (<eref type="inline" bibitemid="RFC5545" citeas="IETF RFC 5545"/>) specification to allow a more compact representation of overridden recurrence instances.</p>

CC/WD 58020:2016 Working-draft
standard Ed. 1 2016-10-28
The iCalendar VPATCH Component

Cyrus Daboo, Kenneth Murchison (VCARD)

<p>This document defines a new iCalendar <eref type="inline" bibitemid="RFC5545" citeas="IETF RFC 5545"/> component that allows small "patches" to be applied to large iCalendar data objects, to allow for efficient data updates. It also describes how this new component can be used with the CalDAV calendar data access protocol <eref type="inline" bibitemid="RFC4791" citeas="IETF RFC 4791"/>.</p>

CC/WD 51022:2016 Working-draft
standard Ed. 1 2016-04-01
DAV Server Information Object

Michael Douglass (CALENDAR)

<p>This specification describes a new XML object that can be retrieved from hosts to discover applications, features and limits for that host or domain.</p>

CC/CD 51015:2015 Committee-draft
standard Ed. 1 2015-11-02
Calendaring and scheduling — v-event URI: An URI scheme for events

Raphael Menderico, Paulo Schlup, Lucia Kristiansen (EVENTPUB)

<p>This document defines the format of Uniform Resource Identifiers (URIs) for calendar events, allowing users to add these events to their calendar application from any source that defines them, like web sites and printed QR codes</p>

CC/S 1301:2013 Published
specification Ed. 1 2013-01-10
CalWS-SOAP SOAP Web Services Protocol for Calendaring

Michael Douglass (XML)

<p>This document describes standard messages and interactions for service interactions with a system that hosts calendar-based information using SOAP. Hosted information can be either traditional personal and enterprise calendar information or services that support XML payloads developed in conformance with the WS-Calendar specification.</p>

CC/WD 58012:2013 Working-draft
standard Ed. 1 2013-01-01
vCard representation of resources

Ciny Joy, Cyrus Daboo, Michael Douglass (VCARD)

<p>This specification describes the vCard representation of resources.</p>

CC/WD 58011:2013 Working-draft
standard Ed. 1 2013-01-01
Schedulable Objectclass for vCard

Ciny Joy, Cyrus Daboo, Michael Douglass (VCARD)

<p>This specification describes a new property objectclass value for the vcard objectclass property defined in [REF] allowing schedulable entities to be marked as such.</p>

CC/WD 58013:2013 Working-draft
standard Ed. 1 2013-01-01
Objectclass property for vCard

Ciny Joy, Cyrus Daboo, Michael Douglass (VCARD)

<p>This specification describes a new property for vCard Format Specification <eref type="inline" bibitemid="RFC6350" citeas="IETF RFC 6350"/> to allow the specification of objectclasses.</p>

CC/S 1202:2012 Published
specification Ed. 1 2012-06-08
CalWS-SOAP SOAP Web Services Protocol for Calendaring

Michael Douglass (XML)

<p>This document describes standard messages and interactions for service interactions with a system that hosts calendar-based information using SOAP. Hosted information can be either traditional personal and enterprise calendar information or services that support XML payloads developed in conformance with the WS-Calendar specification.</p>

CC/R 1011:2012 Draft
report Ed. 1.0.1 2012-02-22
CalWS-Rest - Restful Web Services Protocol for Calendaring

Michael Douglass (XML)

<p>This document describes a RESTful web service for calendar access and update.</p>

CC/R 1011:2010 Published
report Ed. 1 2010-09-13
CalWS-Rest - Restful Web Services Protocol for Calendaring

Michael A Douglass (XML)

<p>This document describes a RESTful web service for calendar access and update.</p>

CC/R 0907:2009 Published
report Ed. 1 2009-06-10
A Recommendation for Minimum Interoperability of Resource Information

Andrew Laurence, Mimi Mugler, Guy Stalnaker (USECASE)

<p>This document is a recommendation from the CalConnect USECASE Technical Committee regarding the minimum interoperability of resources in the calendaring and scheduling domain.</p>

CC/S 0906:2009 Published
specification Ed. 1 2009-06-10
Use Cases for Resources

Andrew Laurence, Mimi Mugler, Guy Stalnaker, Ciny Joy (USECASE)

<p>This document lists use cases that utilize resources within the calendaring and scheduling application domain.</p>

CC/S 0903:2009 Published
specification Ed. 1 2009-04-15
Freebusy Read URL

Eric York (FREEBUSY)

<p>This document defines a standardized form of Freebusy read URL to improve interoperability between client and server implementations, while extending the functionality and utility through the use of optional parameters.</p>

CC/S 0706:2008 Published
specification Ed. 1.1 2008-08-24
Mobile Calendar Interoperability Test Suite

Chris Dudding, Mark Paterson (MOBILE)

CC/R 0805:2008 Published
report Ed. 1 2008-07-29
Mobile Recurrence Interoperability Recommendations

Chris Dudding, Mark Paterson (MOBILE)

CC/S 0706:2007 Published
specification Ed. 1 2007-08-28
Mobile Calendar Interoperability Test Suite

Chris Dudding, Mark Paterson (MOBILE)

CC/R 0604:2006 Published
report Ed. 1 2006-03-16
CC/R 0602:2006 Published
report Ed. 1 2006-01-24
iCalendar Timezone Problems and Recommendations

Simon Vaillancourt (TIMEZONE)

CC/S 0601:2006 Published
specification Ed. 1.1 2006-01-24
CC/S 0601:2005 Published
specification Ed. 1 2005-11-30
CC/S 0507:2005 Published
specification Ed. 1 2005-09-26
CalDav Use Cases

Bernard Desruisseaux (CALDAV)