I'm using the A+ and Google Calendar sync. My UTC is (-3)São Paulo
I found 2 problems when the Appointment is updated.
When I schedule an appointment the sync works and it's created in the GCal perfectly.
But as I said, my config is set to sync both ways, so when I edit the appointment in GCal, the A+ appointment gets synced too, but the time is updated without taking my UTC time in consideration.
1)Create a 10 AM A+ >> Gcal syncs 10AM
2)Edit Gcal to 9AM >> A+ syncs to 6AM and should be 9AM.
Another problem was that if I update the A+ again, the GCal never gets updated with the new time.