At this point, there are just too many contradictions, I'd rather forget and simply accept the absurd.
For example, being an atheist, I don't particularly believe in holidays myself. I do enjoy myself with my family even if it mean a few capitalists make a little more money during the season. On the whole, a meaningless event makes the whole world happy.
I'm of a fairly open religion (Hinduism). So, there aren't ardent rules you need to waste time with.
http://en.wikipedia.org/wiki/Hinduism#cite_ref-Klostermaier_... [1]
If you assume it's a religion, try this. http://en.wikipedia.org/wiki/Hinduism (Ctrl/Cmd + F. "atheist")
By open I mean there is no rigid rule set or algorithm in my culture to obtain salvation or anything like that (going to temple is optional). You could simply say no. My parents didn't bother me after a while (My mum is an orthodox person). I do want to point out that being a "nasthik" (non-believer) is not encouraged, but ignored.