I've stayed up all day before going 36 hours without sleep, it isn't healthy, but it sure did fix my sleeping pattern.
Well, I pulled an all nighter with a friend and then I fell asleep the next day at 9pm. You can do the math on the hours.
I went to bed at 11:30PM last night after working from 5-10PM, and then had to get up this morning at 6:30 AM today for school. I can't actually express how tired I am in words.
Ummm... The most I can remember was about 9am, and then woke up around 4pm. I had a few all nightere, I just took really long naps at the end of them ;D