How to Disable Automatic Time Zones on iPhone
Having your iPhone determine your current time zone is pretty handy, at least if you travel a lot. But if your iPhone keeps changing time zones for no apparent reason or you want to stay in your time zone, you can disable the automatic time zone on iPhone. That way you can set your time zone manually on iPhone. In addition, your battery life might actually benefit from disabling time-sensing altogether and setting your time zone plus the time and date manually.
How to disable automatic time zones and synchronized dates on iPhoneSettings → General → Date & Time → Set Automatically
Simply open up your “Settings”, go to “General”, then “Date & Time” and finally disable the option labeled “Set Automatically” to fully disable time-sensing. Tap the “Time Zone” field to pick the appropriate time zone for your location. Use the blue buttons below to enter the current date and time. We recommend looking up an atomic clock on the web and using it as a guide.
Disabling this feature should keep your iPhone from changing time zones. Note that you will have to always take care of setting the internal clock of your iPhone, when disabling this feature. Especially with daylight saving or when travelling to a different time zone. Usually iPhones automatically change for daylight saving. Setting an incorrect time or date can cause trouble with certain apps or purchases in the iTunes App Stor, as well as you pre-set alarms. Find out more about setting alarms on your iPhone here.