This is a really weird one to vote on... yet my answer will always be more or less 4...

In my final year at school I would stay up until around 2am, and then get up at 6am, so that was four hours... Waht was I doing? Well, I didn't know a proper programming language then, so I was trying to convert some old quick and dirty QBasic programs to the DOS Edition of Visual Basic.

In my first year at Uni I pretty much did the same, whilst trying to do my assignments in Java!

Now, as I place my academic career on hold, I am awake all night, from 22:30 to 07:00 -- working night-shift, and usually only sleep from either around 10:00 to 15:00, or from 16:00 to 20:00...

Mark