I'd say 10 as an upper-limit. And I agree with Jinx that at some age, most kids should stop having any strict bed time whatsoever. This can vary, though; if the kid is a terrible hellion like Shorty apparently was, an enforced bedtime may be in the kid's best interest. But I stopped having a regularly-enforced bedtime when I was 12 or so, and I was fine with it. I'd generally go to sleep between 11-12 on weeknights after that.