Holidays are entirely what you make of them. A lot of people bring up about how Christmas was initially a Pagan holiday, etc., but for me, it's about my faith, because that's what I make of it. The point of Christmas is to celebrate the life of Christ through generosity, charity, etc.
However, to an atheist(I'm assuming, sorry if I screw up), Christmas is about spending time with family, giving to the poor... Pretty much all of the same stuff as me, just minus the Jesus factor. Again, though, this is perfectly acceptable. It's what you make of it.