Teachers are mostly just kind people doing there best and I meant no implication to the contrary. The school system is fucked though and making kids lose sleep is part of it.

During puberty, youth undergo a shift in their circadian clocks that makes it harder for them to fall asleep until later in the night. Meanwhile, they can stay awake longer before experiencing an increase in the pressure to sleep

https://www.apa.org/topics/children/school-start-times

https://www.washington.edu/news/2018/12/12/high-school-start-times-study/

https://www.theguardian.com/science/2025/apr/22/teenagers-bed-early-sleep-longer-sharper-brains-study

More to the original point, you don't need a bunch of scientists with lab coats and clipboards to tell you teenagers don't sleep well on an early schedule, you could just ask one. Not to mention the homework load etc....

Oh yeah, come home from school, do homework, go to bed, go to school. Repeat for years. It's not like people need free time in their lives or anything, certainly not during one of the most stressful deveplomental staged there is.

Adolescent teenagers, however, have a different circadian rhythm from their young siblings. During puberty, the timing of the suprachiasmatic nucleus is shifted progressively forward: a change that is common across all adolescents, irrespective of culture or geography. So far forward, in fact, it passes even the timing of their adult parents.

As a nine-year-old, the circadian rhythm would have the child asleep by around nine p.m., driven in part by the rising tide of melatonin at this time in children. By the time that same individual has reached sixteen years of age, their circadian rhythm has undergone a dramatic shift forward in its cycling phase. The rising tide of melatonin, and the instruction of darkness and sleep, is many hours away. As a consequence, the sixteen-year-old will usually have no interest in sleeping at nine p.m. Instead, peak wakefulness is usually still in play at that hour. By the time the parents are getting tired, as their circadian rhythms take a downturn and melatonin release instructs sleep—perhaps around ten or eleven p.m., their teenager can still be wide awake. A few more hours must pass before the circadian rhythm of a teenage brain begins to shut down alertness and allow for easy, sound sleep to begin. This, of course, leads to much angst and frustration for all parties involved on the back end of sleep. Parents want their teenager to be awake at a “reasonable” hour of the morning. Teenagers, on the other hand, having only been capable of initiating sleep some hours after their parents, can still be in their trough of the circadian downswing. Like an animal prematurely wrenched out of hibernation too early, the adolescent brain still needs more sleep and more time to complete the circadian cycle before it can operate efficiently, without grogginess. If this remains perplexing to parents, a different way to frame and perhaps appreciate the mismatch is this: asking your teenage son or daughter to go to bed and fall asleep at ten p.m. is the circadian equivalent of asking you, their parent, to go to sleep at seven or eight p.m.

Mathew Walker, Why We Sleep, Chapter 5, p 91