The time is automatically adjusted by the station signal when a radio station is switched on. This makes the alarm clock reliably precise. If the radio is not in operation, the alarm clock runs without being reset. This is not a problem as the Wecher clock is very accurate. It's only when you change to summer or normal ("winter") time that there is a problem: the alarm clock only knows about the time change when it has already been switched on, so it wakes you up 1 hour late.

What is meant by Radio Control Clock? Does it mean the time setting via DAB+?

Unfortunately, we cannot answer this question because we have not been able to try it out in such a form. However, I'll put the question in the community, maybe a user can help you :-)