I think it changes over time as well. There was a time when I stayed up late and woke later. That felt like the right thing to do at the time but since getting into my 40s I tend to sleep a bit less and wake earlier. Sleep is also much more fragile, I’ve had bouts of insomnia and I need to be careful with caffeine and alcohol. Sleep deprivation is the worst thing I can do for executive function, I’ll just stare into space all day.