I have found the key is to stay up however long you want, but to never interfere with your waking time (i.e., sleep in). It's probably not science based but I s

I have found the key is to stay up however long you want, but to never interfere with your waking time (i.e., sleep in). It's probably not science based but I suspect for personality types driven to work, there's a desire to not go to bed until things are "done". And there's an equally strong desire to keep sleeping. So they balance. And if you're really pushing the limits, the concept of morning or evening person loses all meaning. Also eat well, drink fluids, shower, and go for short walks.