About 14/15. They started staying up until midnight or later occasionally (sometimes I'd hear a giggle at 2am), which I understand is biological (based on teenage shifting of the circadian rhythm). Mostly they were just reading or talking at that late hour, so what can you do? I certainly didn't enforce anything at that age, and they were bringing home straight As, so I thought, if it ain't broke, don't fix it!
They are in their 30s now and have turned out fine despite a few years of being extreme night owls. Now they have little ones and have to wake up at 6am while I can sleep in. Oh, how the tides have turned
