I have just bought a cheap Saint Leonhard radio controlled watch (time signal from German longwave transmitter DCF77) which is an analog watch, with an additional digital window. As you can see from the attached graph, it loses about 1-1.5 secs per day, but is deemed accurate (!) because it is synchroniseds daily at 3 o'clock W European time. Questions:
1. the station DCF transmits permamently a signal, so why is my watch only synchronised at 3am?
2. I took the painful decision to get up from bed at 5 to 3am, to watch the change, and the following happened..... At 3am precisely the 3 analog hands showed exactly 3am and remained locked to this time, and the digital seconds continued showing a 'slowness' of 1 second. At about 4-5 minutes past 3, suddenly the analog hands moved to the correct position and the 3 hands were exact. The digital seconds had also corrected itself to the exact time. All values were checked with a HERMLE RCC2000 radio-controlled clock, which is synchronised hourly. Question: What's going on, and why did the analog hands stop for 4-5 minutes?