Calendar moves event when changed to recurring event

When changing an event from a single event to a recurring one, the event date is shifted by one day into the future and the time is reset somewhat random.

Steps to reproduce:

1. Create an event with single occurence (only tested events with specific start and end time, but on a single day)
2. Save it
3. Edit it and change it to a recurring event for e.g. 3 weeks