Salaam,
As a Muslim I'm going to say no.
Other religions will want to add their holidays to the calendar as well.
More school days would be taken off since the 5 main religions will have to be recognized in the calendar.
Not good for the school especially during these economical times.
Christmas is recognized as Christianity is the main religion in America.
Though it supposed to be called Winter Break, some still refer to it as Christmas.
Honestly, i think calling it Winter Break is bullshit.
If your christian, go ahead call it Christmas Break.-Your celebrating your holiday.
Same thing goes for stores, the workers should be able to say Merry Christmas to the customers without having to worry about losing their job for promoting their religion.
I'm a Muslim and I'm not offended when they say it.
Ramadan Mubarak!