Circadian rhythm

Lately I seem to get my best work done between 10:00 PM and 2:00 AM. Which is odd, because I tend to be a morning person. Used to get up at 4:30 AM and walk the dog, and then retire in the evening around 9. But the meter keeps redlining, so I just move the stop post...

I'm guessing it will work its way around the clock until I'm back where I started. Weird.