Explain Why School Days Should Be Shorter

I believe that schooldays should be shorter. I believe that School days should definitely be shorter and everyone agrees because kids are coming home tired and fall asleep waking up the next day with nothing done until the weekend and a whole cycle start again. School days are 6.5-7 hours long and because of this stay/work at home parents don't get much time to see there kids and because of this kids get disconnected from their families and don't talk much to them. During school when kids act up and get suspended they lose so much time about 13-14 HOURS GONE!!!! I get that the reason school days are long is because they want to cram things into that schedule but really they aren't cramming anything in most of class time is spent in working