as the daughter of two teachers, I can attest to how hard teachers work. Every night after school was spent with them both preparing work for the next day/week/month/term of lessons. Every Sunday was spent preparing work, and at least one week of every holiday was spent doing the same.
I can honestly say that when I get home from work, I leave work behind. I have never worked on a Sunday and don't intend to start now. If my evenings and weekends were spent in this manner, then I would certainly expect the compensation of more time off during Easter, Christmas and summer.
Also, some of the stories I hear from them and other teachers would make your hair stand on end with some of the cr@p that they have to put up with children and their parents. I made a decision early in life that I wouldn't be a teacher, but I wish lots of luck to anyone who chooses this unthanked career path.