The time is determined via the GPS time signal from the satellites. GPS satellites have an atomic clock and always deliver the correct time. Unlike the time signal transmitter DCF77 reception is not limited to Central Europe; GPS is available worldwide.
No network connection required to determine the time. That makes Global Time the ideal travel companion and saves high mobile network costs abroad if you do not have an unlimited data plan.
With ipcas always the exact time, on the go with Global Time for Android and for your network with the GPS Time Server ipNTP.