All PCs use MicroSoft account to log in, you can use MicroSoft Family to set up screen time for each day, such that block all day from Monday to Thursday, 4pm to 10 pm on Friday but maximun 4 hours and etc.
If the kid needs 30 minutes to 1 hour for homework, they can log in and send request to parent in order to use temporarily. You can give them 30 minutes, 1 hour or longer.