I don’t think government facilities are the right place to observe anyone’s religious holidays. These should be celebrated in the home, the neighborhood, and the religious congregation. It is understandable that, when society was far more homogeneous, people fell in the habit of considering the public school an extension of the home and private associations, but this has not been the case for decades.
So, no religious freedom on public land, only on private land?
How about free speech?