I work the hours I need to work, and sleep when I'm tired. Naps are the best thing!
But seriously. I get up no later than 07.00 every morning - even on weekends - and get to work directly after breakfast. I then work, work, work until 11.00, take a break for lunch, then work, work, work till dinner. After that, I'm usually done with whatever I've intended to do that day, and I can take the evening off. If I'm not, I put in a few hours in the evening, too.
(yes, I'm a workaholic >.>)
I'm usually in bed before 23.00 at the latest, 22.00 on most days.