One of our always reliable radio controlled clocks decided to tell the time almost exactly four hours late all of a sudden. It gets the time from some atomic clock in Germany and has done a great job for fifteen years.
I have replaced the battery and put it in a window to make sure it's reached by the German radio signals. It made no difference. I don't understand how it can malfunction the way it does. The only remedy I can think of is open it and move the hour hand four hours forward.
What would you do?