It looks like late wake times peak from ages 14-19. There's a well-documented circadian rhythm shift affecting teens. Hence schools rejiggering (and Californi

It looks like late wake times peak from ages 14-19. There's a well-documented circadian rhythm shift affecting teens. Hence schools rejiggering (and California requiring by law) later start times for high school students. At the school I teach at, middle school students were taken along for the ride, because at our school we need to be on a common schedule (crossover teachers, MS students in HS classes). Of course, on the flip-side, no one wants to push it too late because of things like sports and outings with family wanting to have some daylight after school; we ended up starting 30 minutes later, but also shortening the school day by 15 minutes (and doing some clever schedule changes to claw back most of the instructional time lost).