Zero

Oooh. That sound sciency and stuff. I would normally just skip a day of sleep and then power through on sheer willpower until it became bedtime :) Ain't no debate who is sleepy enough to fall asleep on those days!... Then again I know some insomniac friends, it's not so easy for some people xP

Good luck! I hope you'll be out of such period soon.
Also, while I don't like being that guy.. *Alcune, not alcuni.

@ Kalesh, I think that was part of the trick. Supposedly if you don't eat and stay awake, your body forces itself to keep awake until it finds food. Then once you actually do so it marks that as your first meal, hence your supposed "morning" XD.