My daughter and I are having issues with calendar entries on our iPhones. Whenever we create a new entry in the Gmail calendar, it appears with GMT despite the fact that all the overrides and time zones are set to EST.
We did wonder whether this was because we visited the UK recently.
Checking the Apple Forums and following advice given, they now suggest this may be a cell provider issue. That's you!
Here is the Apple response:
http://support.apple.com/en-us/HT203483
