There are also mandatory meetings and in-services that must be attended. Generally teachers spend at least a week, sometimes more, after the kids go home for the summer cleaning their classrooms, restocking supplies, removing old posters and teaching items from the walls, submitting the zillion and one required forms and documents and grades. A couple weeks before school starts up again in the fall there is more cleaning, restocking, new posters put up (which the teacher usually pays for out of pocket). Where my daughter teaches school is out a week before Memorial Day, but she's there into June doing the above. School begins in mid- to late August, so once again she is there in early August doing the above. So basically she gets 2 months off. Without pay. Good luck finding a PT job that is filling to hire you for only 2 months.
My son will teach summer school, which, BTW, is exhausting.