Thank you, both, for the information.
I have a diagnosis of bipolar 1/schizoaffective disorder, but I have not yet started medication and I know the closest psychiatric hospital is a couple hundred miles away from where I live, so I don't know how much of a difference that will make. I also know that my school counselor and my teachers are aware of my diagnosis...so I think that would help.
The only time I ever stayed longer than the timeframe you posted was the first time I was ever admitted. That was just because I wasn't diagnosed with anything and they wanted to before they discharged me. I believe I stayed for a couple months, unfortunately it was a waste of time because they still somehow managed to get it wrong lol.
Yes that is generally true from my experiences (which were over a decade ago before my current recovery) and it should be noted once a person is considered stabilized (unless they are starting medication for the first time or going back on treatment in which case that time frame is what they use) they can be released sooner than that. You can find out some specific long term assignments and other parts of class work from teachers and most probably the hospital would allow you to take part of the day in the hospital to work on that.
The school just needs to be informed that you are seeking help from your parents. They don't have to be told it is psychiatric. When I was in college I was allowed to work on coursework in the hospital and also as things improved when I was allowed on pass to go to class on some of the days. Things are more restrictive in that that probably would not occur now but then again due to insurance reasons hospital stays are shorter than my first time (which was in 1990 and was about a month, after that it was always within the time you said if not shorter).