Locking iPhone in a Certain Time Zone
You can disable the automatic setting of date/time in Settings->General->Date & Time. Of course this also means that you have to manually set the time if you actually move to a different time zone on purpose.
You can disable the automatic setting of date/time in Settings->General->Date & Time. Of course this also means that you have to manually set the time if you actually move to a different time zone on purpose.