I could probably stump up for 5 hours sleep if I went to bed early enough. Trouble is though in my house I have kids who get up fairly early so If i get up too early and stay up for ninety mins I may not get that much sleep in after that. I would need to go to bed at about 10pm get up at 3am stay up till 4.30am then go back to sleep. I am not usually very tired at 10pm though.

Do you time the 5/6 hours after the time you go to bed or the time you get to sleep?

I guess if I did 6 hours from 10pm I could still get back to bed for 5.30am, even my kids don't get up that early so I could prob get enough sleep in after that.

Doesn't it make you tired all day though waking up in the middle of your sleep cycle every night?