Calendar:QA CalDAV Support

This is an overview of CalDAV support in Sunbird & Lightning, i.e. supported CalDAV features and CalDAV servers. Please add your experiences, and refine the matrix if needed.

CalDAV Support Matrix

				Moz Calendar Client
				0.8		0.9
CalDAV Server		Features		Access		Access		Sched.
Name	Version	Access	Sched.	Events	Tasks	Events	Tasks	Events	Notes	Help
Bedework	3.4.1.1									Quickstart Client configuration
DAViCal	0.9.5
	0.8.0
Kerio MailServer	6.5									KB Article
SOGo	1.0 RC?								here	SOGo (@Inverse) Demo Server Accounts
Oracle Calendar	10g
Zimbra	5.0.8								here	Client configuration
	5.0.5								here	Demo Server Accounts (see notes)
Darwin Calendar Server	...
Scalix	11.4									Client configuration
IceWarp CalDAV Server	9
Chandler Server (Cosmo)	1.1.0								here	Client configuration Hub Server Accounts
	1.0.0
Google Calendar									here	Instructions (in German)

'Access' refers to CalDAV-access (rfc4791), which permits creating, reading, editing, and deleting events and tasks (todos) in calendars.

'Scheduling' refers to CalDAV-sched (draft), which permits retrieving participants' free-busy info, proposing a meeting time to participants, and gathering the participants' accepts and declines.

Server Legend: SUPPORTED: | UNSUPPORTED:

Client Legend: server+client works: | server+client fails: | not implemented by server:

Diagnosis hints

To narrow possible causes of CalDAV problems in small calendars, (1) set both preferences calendar.debug.log and calendar.debug.log.verbose to true, and (2) click right on calendar in the Calendars pane to reload it. (Set pref via Options / General / Config editor, right click New / Boolean to add it.)

The xml CalDAV messages will be shown in the error console (and in the startup command line shell) with verbose logging.

The kind of scheduling a server claims to support can also be found with verbose logging.

 Look for something like
   CalDAV: Error getting DAV header, status 404
   CalDAV: Server does not support CalDAV scheduling.
 Or
   CalDAV: DAV header: 1, 2, access-control, calendar-access, calendar-schedule
   CalDAV: Server generally supports calendar-schedule
 Or
   CalDAV: DAV header: 1, 2, access-control, calendar-access, calendar-auto-schedule
   CalDAV: Server supports calendar-auto-schedule

SOGo Notes

Reminders/alarms set by Sunbird/Lightning are not recognized nor editable by SOGo.

Weekly bydays: The SOGo webUI has a problem producing rule for weekly recurrences on multiple days of the week (erronously escapes comma, SOGo bug 2003).

Repeat without start: The demo account sogo1 has many repeating tasks with no start or due date, triggering bug 435166.

Chandler Server (Cosmo) Notes

The WebUI does not show dates of tasks, but the server does store dates of tasks edited in Sunbird, and preserves the dates even when the task is edited by the webUI.

The WebUI creates 'notes' by default and stores them as undated tasks (todos).

The WebUI 'Add to calendar' button then allows you to add dates to a note, and when you click 'save' it will turn it into an event.

Clicking the collection (calendar) name in the WebUI causes it to reload. It's useful if you make a change via Sunbird and want to see it in the WebUI.

Zimbra Notes

Password does not have to be supplied in URL. For example:
  http://zimbrahost.example.com/dav/USERNAME/Calendar

To find version of server from Zimbra Web UI, go to help, search for 'version'.

Sunbird/Lightning 0.9 more correctly handles result codes when asking for VEVENTS and VTODOS from a CalDAV URL. Zimbra version 5.0.8 or later is required to fix Zimbra bug 28048 as described in bug 438642, though there is a patch at bug 438642 to workaround the problem that is easy to apply by hand (the file is in the installed /js/ directory). As of this writing, the testzimbra demo server is only running ZCS 5.0.5, so it is broken and requires the workaround.

Zimbra tasks: As of Zimbra 5.0.5, the .../Calendar url does not include tasks, and the .../Tasks url does not work for CalDAV (there is a corresponding url for ics/WebDAV -- in the Tasks tab, in the left column Tasks folder, right click and click the 'sharing' menu item to display it).

Google Calendar Notes

CalDAV vs. GDATA: Google Calendar's CalDAV protocol support is an early prototype and is not recommended; users who just want to access their Google Calendar are much better off using the GDATA provider.

Reminder alarm loop: Google Calendar's CalDAV server does not preserve Sunbird/Lightning alarm properties (Google CalDAV issue 25, Sunbird/Lightning bug 451821), so Sunbird/Lightning will get into an infinite alarm loop. (Events are created with an alarm by default, disregarding Sunbird/Lightning preferences, so just creating an event starts the loop.) The workaround is to tell Sunbird/Lightning to ignore these alarms: in the Calendars tab, popup the menu on the Google calendar, click 'Properties', and uncheck the checkbox "show alarms".

Location URL: As described in the instructions (in German), the CalDAV URL is of the form
  https://www.google.com/calendar/dav/CALENDAR_ID/events
where CALENDAR_ID for your initial calendar is your full email@address. The calendar URLs end with /events, not /user (/user identifies the user account, not the calendar, and is used in Apple iCal). For other calendars, extract the calendar id from the URLs in the calendar settings page of the webUI.

No Tasks: Google Calendar does not support tasks (todo's).

More known limitations are listed at Google Calendar CalDAV Support.