When the watch is fully wound, it will start movement. Gradually, it will fall behind on time. It will be 20 mins, then 1 hour, then 2 hours behind on time until it stops advancing time all together. It appears as if the watch is not unwinding itself, because you will no longer be able to turn the dial more than one or two times before it is fully wound again but then it will not track the time. The pin on the clasp is no longer holding either. 