CalConnect: 7 Things You Should Know About Calendar and Contacts Sharing

  1. What is it?

    Calendar and Contacts Sharing is the process of sharing CalDAV calendars and CardDAV address books between users.

  2. What scenarios and/or problems does it address, or what new advantage(s) does it confer?

    Users of calendar apps frequently have the need to share calendars with others – whether it's a large business sharing a company holidays calendar, an executive sharing a calendar with an assistant, or a family sharing a child's soccer schedule. Similarly, users frequently need to share address books – such as a company directory, a vendor list, or a holiday card mailing list.

  3. How does it work?

    Many of the services offering CalDAV calendar sharing allow a user to share a calendar with other users of the same system (e.g. iCloud) with read-only or read/write privileges. This is done via an "opt-in" process in which a sharing invite is sent from the sharer to a sharee, allowing the sharee to accept or decline. If the sharee accepts the sharing invite, the shared calendar is made available to them.

    This model can be extended to support other resource types, including address books.

  4. Who's doing it?

    CalDAV calendar sharing is already supported by several servers (e.g. iCloud, Apple OS X Server, Fruux and Kerio) and clients (e.g. Apple Calendar and BusyCal). But the calendar sharing specification is an Apple single-vendor draft and not a public standard.

    CardDAV address book sharing is not widely supported as there is no defined specification for implementing it.

  5. Why is it significant?

    There is a need for a public non-proprietary standard for sharing calendars and address books between users on the same system (e.g. sharing calendars or address books between iCloud users).

  6. What needs to be done, and what is CalConnect doing?

    The Calendar and Contacts Sharing Technical Committee is chartered to extend the existing draft calendar sharing Apple specification to support address books and other resource types, as well as revising the related draft caldav-notifications specification. This will be accomplished by reducing the scope of the current specs and refactoring them into multiple smaller specifications focused on a specific resource or notification type. To that end the committee will define foundation specifications for WebDAV notifications and collection sharing, with sibling specifications for CalDAV sharing, CardDAV sharing, and other resource types.

    A separate CalConnect Technical Committee, Federated Shared Calendars, is working on a related standard for performing intersystem sharing between different systems (e.g. sharing calendars between iCloud and Google).

  7. What are the implications for calendaring and scheduling?

    Defining and publishing public standards for calendar and contacts sharing will lead to greater adoption and compatibility between CalDAV and CardDAV clients and servers, thus improving functionality and interoperability for users.

Need more information?

WebDAV Resource Sharing
WebDAV User Notifications
Calendaring and Scheduling Glossary of Terms

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