school nights is usually around 11:30 pm-2:30 am, weekends are usually all over the place. sometimes 10 pm, sometimes 5 am.
12 as well, but I'm trying to go to sleep earlier. I'm honestly surprised that my friends sleep at like 9 pm still.
3am+ anytime, though on exam days it's probably no sleep because i'm probably cramming everything in my ass in the last night
I'm very much a morning person, I don't really do late nights that well lol, so 9-9:30pm school nights and 9:30pm - 10:30pm weekends.
Usually it's always between 12am-5am, unless I'm really tired, which then I may be asleep at 11pm. If I go out for the night, I'm probably asleep by 7am. I used to sleep at like 1pm and all sorts of sporadic times but I've changed a bit since due to uni and hated wasting most of my day sleeping :)