thanks so much for your suggestion.
i found something, plugin “qTranslate-X” causes this problem. i will try to fix myself
The time does not appear on bookings list. But if you click on a booking then a pop-up will appear and the time is there.
In WordPress Setting i have Date Format: d.m.Y and Time Format: g:i A (12:02 PM), Zeitzone is Berlin. I will test now as you suggest.