Things have changed a bit since the last time I had anything to with it, but you can read the Android source code: https://github.com/android/platform_framework

Things have changed a bit since the last time I had anything to with it, but you can read the Android source code: https://github.com/android/platform_frameworks_base/blob/master/services/java/com/android/server/NetworkTimeUpdateService.java https://github.com/android/platform_frameworks_base/blob/mas... NITZ is terrible. You only get one-second accuracy, a GMT offset, and a DST flag, and they can all be wrong at the whim of someone at the phone company.