Our government was mostly founded by religious Christians. However, our government was founded as a SECULAR (i.e. religiously neutral) state, not beholden to religious law. That's why we don't have a state church. Certainly our common law and legal instutions were influenced by Christianity and Christian civilization-- still, there's no question that the Founders envisioned the country as a religiously neutral government populated by a religious citizendry.
Fourth, as a mom with 3 children in school, I understand about the 1/3 absent policy. This also has to do with money trail I mentioned in three.
It has nothing to do with a "money trail." It has to do with the fact that religious minorities like to live near one another. Therefore, some school districts will naturally have large proportions of Jewish or Muslims students and teachers. Let me ask you this-- how could a school practically function if 1/3 of teachers don't show up? Schools don't have that many substitutes on retainer.
How about my honor's classes in high school, which thanks to my people's superior brain power (half-sarcasm), were about 60% Jewish. Would you acknowledge that at least those should be cancelled, or would you seriously hold class with fewer than half the students, just for the sake of only recognizing Christianity?
Oh, and by the way, what Calendar do you use?
Depends, if I need to schedule appointments with people (few of whom are Jews) I use the Christian calender that's universally known in this country. Conversely, I celebrate life-cycle events (birthdays, grandparents anniversay etc.) according to their placement on the Hebrew calender.