If you're religion doesn't allow you to celebrate certain things but school is still in session do you

I know religion is important but I know a lot of people don't send their kids to school due to the holidays and they don't want their kids caught up and improperly influenced, but my thing is if you're teaching them at home they'll know what is allowed and what's forbidden,

For example one lady didn't send her kids to school because they were having GREEN Eggs and ham day, when all she had to do is write a note stating my children cannot eat pork, please excuse them from the assignment, and have them do something else, these days still count against you and your child