How does the Google Calendar sync work?
Tweek instantly imports 50 events from your Google Calendar from the day the sync occurs. After that, every new event added to your Google Calendar will automatically be synced with Tweek.
This only works one-way (Google Calendar -> Tweek), which means if you change an event in Tweek, it won’t be changed in your Google Calendar. Similarly, tasks added to Tweek won’t automatically be added to your Google Calendar.
Please note that Tweek doesn't support public shared calendars (e.g. public holidays) as well as alternative calendars such as Lunar (Moon Phases) calendar, Sports calendars, etc.