CalDav Calendar displayed wrong and Timecondition not working

I had the problem sine several weeks that i had setup a Calendar in FreePBX which loads the Calendar Events from a CalDAV Source (Kopano) but the time's are displayed wrong.

In the Source their are some example time events from 08:00 to 18:30 o'clock, but freepbx calendar display it with 09:00 to 19:30 o'clock . The events are all timezone Europe/Zurich , so their shoul'd be no different between the time.  I Attached a .ics file which will be automatical provided if i open the caldav source with a browser.

This calendar is connected to a time conditions which controls the voicemail so if the time condition is matched, the phones shoul'd call, if the condition is not matched the voicemail shoul'd be answer with a message.

Now was 10:30 o'clock and when someone called the number their was still the voicemail which answers and not the phones. I changed now back to the classic approach with a timegroup but this very static. The calendar is the optimal variant to enable voicemail control for users with limited rights.

In the Modul Admin Page the version for calandar is 14.0.3.9, and an update check say it's up2 date.