How many hours do you sleep each night doing school night and the weekend?

I'm a doctor so I hardly get any sleep at all. I get maybe 4 hours maximum on the weekdays so I make up for it by sleeping practically all day in the weekends. I recently saw a study online that said most people need at least 8 hours but there are some, usually elderly that only need 7 hours. Teens go through a period where they seem to need more sleep and some sleep up to 12 hours. There are so many changes taking place in a teens body that is affects their sleep. So I'd get at least 8 hours per day if I had to say how many we're supposed to get every day.

On school nights I usually sleep 5-6 hours too. But my school nights are Monday nights to Wednesday nights. Thank goodness for college and being able to choose your own schedule. On the weekends I tend to make up for lost sleep.. even though that's not good for your body clock.

Back when I was a student, I sleep 4-56 hours depending on the no. of homework i have. Its really not enough and sometimes I end up sleeping on the car on my way to school. During weekends I sleep for 12 hours! My mom doesn't approve though. And I always wake up with a headache.