Time is wrong after reboots stucked at 27th august

[user641]

That will happen if the phone cannot obtain the current date and time from the internet. In order to preserve date and time under those conditions you need to go into Settings and turn off automatic date setting. (That's what I do since I do not use mobile data and have the wifi turned off most of the time.)

I see, but I always have wifi and 4g internet, that's why I found it strange.