My wife's AT&T iPhone5 changed nicely as we drove from TN to MT and back. As well as when the time change occurred. My AT&T MVNO, Consumer Cellular, changed nicely on the same trip (MotoG it is 3G, not 4G). My MotoG is running 4.4.4 of Android, and is a 'unlocked international GSM' version, as I purchased through Amazon.