I remember the time when I revealed to my family I was a Humanist. It was at our family Christmas shindig. I wore my Humanist Community T-shirt. My Grandma asked me if I was a heathen and some cousins asked how could I celebrate Christmas if I was an atheist. Holidays may have strong religious ties but atheists can enjoy them if the believers work a little harder to include us.
Herb Silverman wrote a couple of posts about the interaction of atheists and believers on the holidays.