Wrong timezone in Shared Calendar from NextCloud 12

I installed NextCloud 12.0.3 and Calendar app. Everything was fine and then I shared the calendar to Google calendar using webdav:// link. However on the Google Calendar I noticed that the timezone was UTC:

Nextcloud calendar shared in Google calendar

instead of my correct timezone UTC+8

My colleague’s (Google) calendar

In the whole NextCloud system including Calendar app settings I didn’t find anywhere to define the timezone. The server timezone and the php.ini (from all the php7 module like cli/apache2/…) were all set correctly. The time on the shared calendar was correct to (for example, event in 12pm was shown correctly). The file’s timestamp was correct too. Just don’t know where the timezone was defined and set.

Any ideas or replies are very appreciated.

Does anyone have ideas about this question? Thanks in advance

I think the events are always stored in UTC. Only the calendar interface then uses the timezone from the browser. Most clients then show the events in the default timezone of the device…