I do not celebrate any religious holidays.
I am a "from the cradle" atheist. Don't think my parents particularly enlightened though. It was just neglect, masquerading as "allowing choice."
I am from about 2 generations ago, and when I realized (in isolation - no internet at the time) the malicious and dehumanizing nature of religious dogma (and indeed all dogma), I began to see religious holidays as anti-human events intended to promote an anti-human agenda. I gave up celebrating them for that reason - they are anti-human symbols of anti-human mentalities.
Since that time, not celebrating hatred of humanity has become pretty much a defining part of who I am. It is unthinkable at this point that I should return to it. Unfortunately for me, I suppose, the next generation's crop of budding atheists came in the form of almost deprogrammed religious people, who still bore fond memories of religious holidays - and a prime topic became whether people should or should not celebrate. Some of the deep programming, it seems, remains.
I rarely speak in terms of "shoulds," so I was at a disadvantage against a huge number of atheists leaving their religions, and wanting to keep the old, good times alive, despite what they were symbols for. They moved into redefining holidays in their own terms or reclaiming them from religion B back for a better/nicer/kinder religion A or some other such rationalization. I always saw the proper approach as creating new celebrations based on humans rather than dogma.
Hell, even our "atheist" groups are mostly led by people who have only recently lost their faiths, so now we see most atheists carrying baggage from their earlier lives, which they try to inject into atheism. They suffer a cognitive dissonance about celebrating holidays that I do not. Of course this is sort of understandable, since religions routinely seek to assimilate any celebration into their dogmatic terms.
The latest "millennials" generation is even worse, having re-embraced extreme dogmatism in the form of social engineering. Because, you know, they have it all 100% right *this time.*
That I see it this way does not add to my popularity, even among atheists, and when I describe an atheist or humanist accepting a xmas present as being like a jew accepting a present wrapped in swastikas, that doesn't sit well with some. Most are still unsure whether religion is humane or not whereas I recognize religious charity as a mere PR campaign. It isn't charity at all and it isn't about humans at all - it's an indoctrination technique.
However, that said, that is how I see it, and I make no demands or claims on anyone else. Celebrate what you choose to. I never really had a family, so familial reasons do not apply to me, as they might to others.
I shall continue to raise a toast on Darwin Day or on Carl Sagan's birthday and hibernate during religious celebrations. That is my way, and it helps to maintain the integrity of who I am.
