Start at 10am, go till 4pm?
In the US, it's common for schools to start at 8:00 or even 7:30. Recently there has been a push to start later to give kids more time to sleep. So pushing it back to say 8:30 or 9:00 (but not shortening the day, so basically everything just gets pushed back, and the kids stay up later, and need more time to sleep...).
The reason is purely practical- start times need to be staggered to allow schools to share buses, and having high school students get home first means they can look after their younger siblings until their parents get home from work.
Elementary school, 8am - 2pm
Middle school, 9am - 3 something (3:20pm, I think?)
High school, 7:40am - 2:55pm
It’s completely ridiculous, especially considering how sane many (most?) countries in the rest of the world have it.
Granted, even if they were on 2 income households in the 70's, it was also a time where 10YO's were trusted to get home or even walk home unattended, so it'd only be an issue for the youngest primary students. That may still be the case in some Asian countries today, but certainly not in the US.
For secondary school you can elect to have early and late classes or simply opt out of a period if you have the curriculum met. but I've never heard of a student starting later than 9.
>Who takes care of the kids after parents go to work and before school starts?
that's generally why primary students start earlier than secondary students. By high school it's no big deal if the student is by themselves getting ready to leave at 8:30 if the parents need to take off at 8.
ADDED: I often think I couldn't handle high school today.
I'd quit a job as soon as I could find another, if it demanded of me what high school did. Hell, I'd quit based on the consistent 10+ hour days and constant due-tomorrow deadlines, let alone the rest of it like the before-the-sun's-up start time, having to ask permission to go take a piss, sitting in crappy chairs in bad lighting for back-to-back ~hour blocks all day, and having to keep "working" indefinitely with people who won't stop being shitheads in ways that'd get them fired from most any job inside a week. It's insanely terrible.
Like, there are multiple bad things about it that I've never had to tolerate in such abundance and variety even in low-skilled jobs I've held. WTF.
College and adult life are so much more chill than high school. It was a real shock, leaving there for the wider world. So glad the people who were like "this [shitty thing] is to prepare you for the real world, which is way harder and less forgiving!" or "enjoy it, because this is the best time of your life" were entirely wrong. I'd probably have offed myself by now, if they'd been right. Four years was barely tolerable—a lifetime of that, or worse? No, thanks.
Everything else is much worse for how I think. I don't get to choose how to time my schedule, the curriculum is mostly fixed (you would always have math/english/history, some language for 3/4 years. You only choose an elective and maybe 1 year of science) and homework tended to stack up constantly because every class was 1 hour M-F. And yea, as you mentioned it's absurd having 1 day due homework spring up when you may or may not be preparing for some other project, or test, or even competition.
You also were much more pressured against taking time to yourself. You can skip a class or take a sick day in "the real world" if you need a break or emergencies come up. those "perfect attendence" rewards were the worst grift of the education system.