We did some tests, and it seems that the firmware stores the system time in non-volatile memory from time to time. When rebooting, without network access, the system time still incremented monotonously from the time before the reboot. (which would be great!)
Is that correct?
What is the system time on a brand-new device that boots for the first time before it first connects to the network? (We can’t test that right now, have no brand-new devices left) Is it something close to 0L, or some arbitrary time like January 1st, 2010?
Also, is there some way to get a callback or such when system time is adjusted by the firmware, particularly if it makes a big jump?
(I’m asking because we are trying to integrate some measured values over time, and if we don’t understand the system time behavior, our integral will be completely off — e.g. we might have thought we integrated over 5min, but it was from 1970 or 2010 across a system time set to now.)