What would they do for the hours after school finished normally or if work on weekends?
Sounds like a work / life balance problem. Companies will have to be made to change their working practices, allow more remote, flexible working hours and reduced time.
UK is, very, slowly starting to move to a 4 day week for work (reduced hours, not cramming in 4 days x 10 hours). The productivity increases along with recruitment make it worthwhile. My company isn’t there but 35 hours + 50 days holiday so not far.
That would solve the 4 day school day. Also allow for parents to educate their kids for 1/2 a day if needed.