
The calendar's timezone cache holds only timezones already received or added to the calendar, thus when asking it for a timezone for "the first time", it returns NULL and a wrong timezone is used instead. The get_timezone() does not do any I/O when the timezone is already cached on the client side, thus it's fine to use it. This could exhibit with non-recurring events, which use custom time zones, in which case the event is shown in a wrong time. Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2145>
Please keep in sync with gnome-panel.