The university calendar can be integrated with the integrated calendar (formerly as Lightning add-on) via CalDAV protocol into the e-mail program.
First, the university's personal email account should be set up in Thunderbird. The instructions can be found at:
https://www.uni-bielefeld.de/einrichtungen/bits/services/kommunikation/e-mail-und-kalender/anleitung/postfach-konfiguration-unter-thunderbird
To subscribe to shared calendars, the same configuration has to be done as for the personal calendar (see above).
At the place where the address is entered, the e-mail address of the calendar to be subscribed to has to be entered.
Example
Max Muster wants to subscribe to the shared calendar of Berta Musterfrau. The address should look like this:
https://caldav.uni-bielefeld.de/users/berta.musterfrau@uni-bielefeld.de/calendar/
In order to subscribe to own sub-calendars, the same configuration has to be done as for the personal calendar (see above).
The calendar name of the sub-calendar has to be appended at the place where the address is entered.
Example
Max Muster wants to integrate calendar "Archive_Calendar". The address should look like this:
https://caldav.uni-bielefeld.de/users/max.muster@uni-bielefeld.de/calendar/Archiv_Kalender/
Important:
A release for the main calendar must also exist for the release of the sub-calendar. For this, at least the authorization level "Availability only" must be assigned.
To subscribe to shared sub-calendars, the same configuration must be made as for the personal calendar (see above).
The e-mail address of the calendar to be subscribed to and the calendar name of the sub-calendar must be appended at the point where the address is entered.
Example
Max Muster wants to subscribe to Berta Musterfrau's shared sub-calendar "ProjektX". The address would have to look like this:
https://caldav.uni-bielefeld.de/users/berta.musterfrau@uni-bielefeld.de/calendar/ProjektX