User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36
Steps to reproduce:
I have a birthday allday event in my 184.108.40.206 calendar that begins on 03.05.1973 (DD.MM.YYYY) and ends on 03.05.1973. The time zone is shown as "local time", the grayed-out start and end time as 23:00. Repetition is set to "yearly" with no end.
The event is shown on 04.05.1973 in all views. The date and the time stamps cannot be changed, even with "all day" (Ganztägig) unchecked.
If "all day" is unchecked, the time zone is shown as "Europe/Berlin" and the date jumps to 04.05.1973 19:00-20:00. "00:00" or "00:01" are not accepted as a start time, instead the entry field jumps to "22:00". If I select "03.05.1973" as the start date, the entry field jumps to "02.05.1973" automatically.
The event is shown on 03.05.1973 in all views. With "all day" unchecked, it should be possible to change the date and time. Both bugs can be reproduced, even with other calendar entries.