I'm in the process of writing an app for Android. I need to allow my users to capture their current location & log the date/time that this happened. The catch is that the date/time cannot be something that the user can change by adjusting the date/time on their device. 

Can you point me in the right direction for obtaining the Cellular Network date/time when using location services for towers, and also how to obtain the GPS date/time.

Any help is appreciated, thank you!