After my recent move to NYC, I discovered that my Google Calendar was 3 hours off from my iPhone calendar. No worries, just go into the iPhone Settings — General — Date & Time and make sure the phone understands the time zone. Huh, well, it’s set automatically, over the air.
There is a setting in Google Calendar for time zone. Changed that. No joy.
Finally, I looked deep into the iPhone’s Mail, Contacts and Calendar settings — and way at the bottom of that screen, you set the time zone for the calendar. And it wasn’t the same as the phone’s time zone. Sheesh. Now my calendars are synced up.