I use RESET Pin and PE. I watched that after RESET the initialization sequence copy the start time, hard coded from PE, to the variables holding time and the current time is lost.
Is there a methode to save and copy the current time over PE sequence?
Reset pin and power-on reset are two different cases. Which one do you really mean?
Power-on reset without some battery backup is not really possible. Unless you don't care for the date time staying frozen at the time of power down.
Reset pin: Just make sure you don't clear the variables holding the date time during initialization. Possibly add some CRC to verify correctness. Again, the date time will not remain too accurate over repeated resets out very long reset durations.