Okay, actually, the problems seems to be a little bit more complicated:
1. Creating a new event on Rainlendar (Version 2.12 (b136) 64bit, e. g. on february 10th, 9 am to 6 pm. It synchronize it with Google Calendar, but if I check directly again the event, the time changed automatically to 10 am to 7 pm.
2. If I open and change the time to the correct one (9 am to 6 pm), it still keeps the time 10 am to 7 pm. If I save the event with 10 am to 7 pm, it changes it to 11 am to 8 pm. I guess it might be a problem with the time zones (I am at UTC + 1h)
2. Checking my android phone: Google calendar shows two times for the event: The correct one (time zone UTC + 1h) as well as the times in UTC (all in one event).
I hope you can follow my description