I see late night hacking as a tale of diminishing returns. For an extra hour of wake, how much less productive will I be tomorrow? How much earlier could I get

I see late night hacking as a tale of diminishing returns. For an extra hour of wake, how much less productive will I be tomorrow? How much earlier could I get up if I go to sleep earlier, and how does that time's productivity compare to now? This translates to: if I'm tired I go to sleep. Unless I have a deadline for the next day.