This is the best time of year to work customer service. People are nice to you more often than not. I even receive the occasional "Merry Christmas". This is frowned upon. Because freedom of religion only applies to non-Christians. At least that is what it seems like.
I know that the good will and pleasantries will go out the window on January 3rd. Most everyone will be back to their rude and terrible selves. So, Merry Christmas and if you aren't Christian and/or that offends you, don't read it.