Time

Okay, something weird is happening, and I'm willing to listen to any theories about what might be happening.

For the last four nights my wristwatch has stopped in the middle of the night. The first time it happened I naturally assumed that the battery had died, but when I reset it in the morning, it resumed running and ran fine all day - until that night when it stopped again after I had gone to sleep. Each morning, and again, this has happened the last four days, I have reset it, it has run and kept perfect time during the day. The only pattern I can see is that it seems to stop shortly after I've fallen asleep, so at 11:00 pm or maybe a little later. The one theory I had, since debunked, was that I was putting pressure on the stem of the watch somehow, but that doesn't seem to the the case, so I'm mystified.

Any ideas? 'Cause I'm out. Nancy says it's my biorhythm

UPDATE: In the end, it was the battery. The jeweler theorized that the extra power needed to turn the calendar wheel around was more juice than the dying watch could provide, hence it stopping around 11:00 every night and then running the next day when it didn't need to turn the calendar wheel.

I learn something every day.