Here is another post that to me looks like the same problem: https://github.com/espressif/arduino-esp32/issues/572 The problem here is that the user found that he couldn't deepsleep for longer than an hour. I ran into this with my project as well. The longest you can deepsleep for is the 4200 second...

Here is something interesting from this post: https://arduino.stackexchange.com/questions/12587/how-can-i-handle-the-millis-rollover Note on micros(): Everything said here about millis() applies equally to micros(), except for the fact that micros() rolls over every 71.6 minutes, and the setMillis()...

Something else I have noticed is that the time can also go backwards. Looking at it one instance it will be say 2200 seconds. Then it sleeps for 10 minute, and when it wakes up, the time is 2180.

I am trying to resolve why the time gets reset after around 4200 seconds while it is in deep sleep. If you track it, the time tracks fine between waking up and going to deep sleep, except that it goes back to zero sometime after it reaches the 4200 mark. This piece of code demonstrates it: time_t no...