Took my 7042 from CST to PST. The 7042 connected fine to the new network but did not change the time... I do have the time set to use network provided time zone
I believe the location service in android uses a number of sources to figure out your position in relation to date and time. Sometimes this information is provided by the ISP . Sometimes for more accurate fixes google uses its signal maps to identify wifi access points around you to triangulate your device. So it most likely was an error of the network you connected to which gave you the wrong time offset.