I do find it odd that so many people seem so determined to define "Christmas". Whatever you do or don't do, whatever you do or don't call it, it's a public holiday that anyone can spend as they wish. People can spend it as areligiously (or as religiously) as they wish.
It's the same old bollocks around marriage, this bizarre idea that some belief owns it, and therefore we should all think of it the same way, do it the same way, or be forbid from calling it marriage.
Winterval, Christmas, whatever. Christians don't own the sodding day, neither do pagans, neither do the Cola Cola corporation. It's a mish-mash of different kinds of celebrations, traditions, rituals and customs anyway. Why not pick 'n' mix it?