Hmmmmmm it depends. My official bedtime is about... 10:30 EST. That's when I'm supposed to be lights out in bed and asleep. However, most nights I'm not tired enough by then to go to sleep. The latest I think I've ever stayed up (at least in my recollection) was one time, when I was really really upset and contemplating suicide, I stayed up until about 4 AM EST. That's not usual though. Usually I stay up, at the latest, 1:30-2 AM EST.