Some people are just genetically nocturnal. I had one grandparent who was early to bed. Everyone else in my family is somewhere between 12 and 2 am. As we get older we seem to need less and less sleep though. By 70, my nan was averaging 4 hours. Up to bed at 1, up a 5am to teach her 6am colege classes.

My other grandma slept 3x 2 hour bouts thought the day my whole life. 2hr nap around lunch, another after dinner, then shed be up til 2am, and 'go to bed' just to be back up around 4am. I think that had somwthing to do with her living most her life off the grid and having a wood stove got heat her whole life.