If you want to go to school or send your kids to school during Christmas, go ahead. Noone will be there, but it is your right to do so. Like it or not, the majority of this country is christian and therefore we get a christmas holiday. You want off for yom kippur? Take it, but good luck convincing your boss on that one. However, freedom of religion means that if you really wanted to do it, noone can stop you. So enjoy.