Android
Set Date and Time Automatically or Manually auf Android
Android sets the date and time on its own as soon as the device registers with your network provider. This works through the Set time automatically option, which pulls the current time and time zone from the mobile network the phone connects to.
This automatic sync is reliable in most cases, but it can drift or show the wrong zone right after switching SIM cards, roaming abroad, or using a weak signal. It also gets in the way if you need to set a custom time for testing, screenshots, or a device without a SIM.
To take control of the clock yourself, disable the automatic option first. Go to Tap on Settings ➔ Tap on System ➔ Tap on Date & time ➔ Enable or disable Set time automatically.
Once the toggle is off, new fields for date, time, and time zone appear on the same screen. Set each one manually and Android keeps that fixed value until you switch the toggle back on.
Turning the option back on hands control back to the network provider immediately, overwriting any manual value you entered. Leave it enabled if you travel often and want the zone to update on its own.