System Clock / Date Time

There might be several time giving sources like GNSS, NTP, etc that can be used to synchronize the system clock and other clock dependent parts.


Chrony is able to perform such clock synchronizations. For further information please have a look at Chrony. Chrony is also able to synchronize the HW clock (RTC) automatically if it drifts away.

Another tool to synchronize/handle/update the HW clock (RTC) is timedatectl which competes against chrony. This means be cautious when synchronizing/updating the HW clock manually

HW Clock Synchronization/Update

As described in section above the RTC can be updated using different tools. The following sections show how this can be performed.


NOTE: Using timedatectl you are able to update the HW clock manually.

If no time source is present no update takes place automatically. Then a manual update is possible with:

timedatectl set-local-rtc n

Please read also the timedatectl man page when using timedatectl.