It becomes irrelevant when you're ahead on all of your studies (or if a 6 hour day is completable by you in an hour).

I am in the group that took 1-2 yearly week long vacations in elementary school. Nothing was lost, since I just did the week of required work in half a day after returning from vacation.

Education is important, not school. So long as school is a means to receive education it is important. A lot of people don't think it is anymore.