Full Sync is needed when new Google events don't appear in Calendars 5.
During the process all data in Calendars 5 is replaced by the events and tasks from your Google Calendar account.
Note: Full Sync deletes all Calendars 5 events, so if there are some that were not synced to your Google account, you can assign them to a local calendar:
As Full Sync does not involve Local calendar data, these events will not be deleted.
To perform Full Sync: