13y old
11pm on the weekends and we wake up by 9ish if he isn't already awake (often he wakes naturally about 8:30.) He does much better when he is in bed at a decent time and doesn't sleep in too late.
14y
Often puts himself to bed before 11 (closer to 10-10:30) and though he is naturally an early riser (up by 7am) he recently told me that he is less sluggish through the day if he is up by 6, so he started setting his alarm for 6 on weekends (that is the time he gets up for school.)
I am naturally a morning person and am NOT a night owl. I never pulled an all night in college or grad school, and was routinely in bed by 11 in college and took 8-9am classes (and went!)