My sleep schedule is typically seasonal unless I have some on going health issues. Winter we have 14-15 hours of darkness starting at 6:30-7pm so I'm usually asleep by 8. Summer it doesn't really get dark until after 10pm, and also summer is usually when I have my SUD relapses so I fall asleep around 1-3am.

Most annoying is when everyone else is a braggart about their ability to sleep by snoring all freaking night.