I admit it, I go to work very late. Most people think its because I go to bed very late or I just don't sleep enough. Not so. I for ages tried sleeping 9 hours a night starting at 10pm and 11pm. But I always felt tired or not with it between the hours of 9am-1pm. So since I shifted my schedule to sleep at about 2am and go to work about 11am I've felt a lot better. This is why I can clearly understand the New York Times story about Teenagers getting better grades when they go to school/college later rather that earlier.
Research shows that teenagers’ body clocks are set to a schedule that is different from that of younger children or adults. This prevents adolescents from dropping off until around 11 p.m., when they produce the sleep-inducing hormone melatonin, and waking up much before 8 a.m. when their bodies stop producing melatonin. The result is that the first class of the morning is often a waste, with as many as 28 percent of students falling asleep, according to a National Sleep Foundation poll. Some are so sleepy they don’t even show up, contributing to failure and dropout rates.