I was joking at work about the process to update the wall clocks with the right time. Someone told me there is no process. They update themselves.
It turned out there is a long radio wave that transmits the time to all of Germany. It is connected to another German atomic clock that’s linked to the German master clocks. It is called DCF77.
There are even watches and clocks that have these radio receivers. I searched on Amazon and found many. You don’t have to set them. They just get the radio signal and set themselves. They will tell you if they are unable to receive the signal. That’s when you should set them manually.