I stay up late out of necessity. I work from home (on my startup) and I have a large family. That means the only time I get uninterrupted time is after 11:00pm. I need the uninterrupted time for the difficult problems. Other work I can bang out during the day.
The down side is I sleep until noon.
When I had a 9-5, I stayed up until 2:00-3:00 got up at 8:00 and was in the office by 9:00. I would catch up on sleep over the weekends.