When mangoh updates its UTC time?


My last question on time issues.

Under which rules mangoh updates its time to the correct UTC time?

To put it more clear:
1- Is it done one you get connected to the network?
2- When you activate a data connection through some time service in linux?
3- Or when you get a correct GNSS solution via the time provided by the satellites.

And finally, how could I know that this time update has actually happened?

Thanks a lot guys.