I stay up until about 10:30 on the weekdays, or in bed on the chat till 1 AM (ssshhh!) but on the weekends I go to bed at past midnight. When I have a vacation, like the one I'm on now, I can go to bed ridiculously late, like a few days ago I went to bed at 5AM and woke up at 11am, or 2am. I like staying up very late because it's quiet and I can read or play a DS game or whatever I want, and just go to sleep when I feel tired.