No. That cell phone can wait.
Where I live they do. The school day for high school starts at 7:30. They let out at 2:45. That is 7 hours and 15 minutes. Then take out 40 minutes for lunch. That is 6 hours and 20 minutes. That is not even accounting for the time to change classes.
When you leave school you will put in 8 hours (or more) with only a 30 minute lunch. Plus while you probably not accounting the change of class. That getting up, stretching your legs and walking makes a big difference when you are chained to a work station.
In other words quit your whining and enjoy having it as good as you do, because it isn't going to get any better.
I'm not sure where you are going with your logic.
School curriculum typcially involves at least 7 hours (including a lunch period) .. The start time of the school day determines the end of the school day.
In high school class started at 7:30 ended at 2:45
Per state and national regulations you have to be in school a certain number of hours per year. So the choice is a full day as you go now or to go more days (less vacation).