Created attachment 325817 [details]
Screenshot of the problem.

Since the update from Gnome 3.18 to 3.20, I have a problem with
displaying the correct starting and ending times of events of a calendar.
I added that calendar to evolution-data-server as a remote calendar "On The Web".
The calendar does not attach a particular timezone to the events.

In the application evolution itself, the dates are displayed correctly,
however both in the top bar of gnome-shell and in gnome-calendar, the
same date is diplayed 2 hours off for all appointments of this calendar.
For example, an appointment that starts at 13:00 is displayed to start at
15:00.

See also
https://mail.gnome.org/archives/evolution-list/2016-April/msg00038.html