After not syncing at all for a month or two, the Garmin Connect Calendar is again appearing on my Google Calendar. However, the sync is not working all that well.
I've created two entries in my Garmin Connect Calendar. First, a workout on November 18. Second, an event on November 21.
Both of these entries show up on my Google Calendar. The workout shows up as an all day event, exactly as I'd expect. However, the event shows up a day early, and only for one hour starting at 7:00 pm Eastern Time. It's as if the Garmin Connect Calendar syncs Events as if they're one hour long at midnight UTC.
Until the Garmin Connect Calendar lets you set events with a specific time and time zone, they should be treated the same as workouts. Set them up as an all day event on the day scheduled.