I currently have 2 issues (not sure if they are related), but recently our external NTP reference was turned off. I have since added a new reference, but since the old reference was removed, any phone I add to the system does not update the time. It stays on the default US time.
Looking into the user locale, it has "Built In" and the Network Locale is "United States". Even if I edit the phone, and change the network locale to Australia, the locale still displays "United States".
I have checked the Device Pool, Location, Date/Time Groups, and it exactly the same as a working phone displaying the correct time.
I have also removed the phone from call manager, performed a hard reset on the phone - same result