What time do you usually go to sleep? What time do you usually wake up? What is the middle of those two times—that is, what is your midpoint of sleep? (For instance, if you typically fall asleep around 11:30 p.m. and wake up at 7:30 a.m., your midpoint is 3:30 a.m.) Now find your position on the following chart, which I’ve repurposed from Roenneberg’s research.
