Just quit my job so around 2 AM as of late. In my ideal world it'd be around 11 or midnight but I'm a night owl and it's hard enough falling asleep as it is.
I'm really big on keeping a relatively regular sleep schedule as I think it's important for both mental and physical health (plus I'm nearly 23 and trust me, around this age you can quite quickly start to find that staying up until 6am like you did in your teens isn't so fun for you any more, especially if you have a day job), so I try to be in bed between 9 and 10pm, and usually wake up around 6:30am. I genuinely feel tired all day if I get less sleep than 8-9 hours!
Usually I sleep around 12-1am, but recently I've been going to bed a lot later because I've been playing games with a friend in the UK. Timezones suck and I'm usually the one staying up late since I don't want to wake up early just to play
4/5am usually, sometimes a little earlier or later, I don't have a set schedule, my partner and I have different time zones and I like to stay up with him