More than 12, but no per night. Usually I stay awake working for 2 to 3 days straight without any sleep, surviving on constant coffee and energy drinks. After those 2 or 3 days I usually crash for 12-14 hours. It's not healthy so I do not recommend doing so. It seems that no matter how many times I get my cycle in order, it will still get out of order. Heck, I don't even bother anymore, guess it's just supposed to be this way.