Does athists celebrates Xmas or Christmas/

I knew a atheist who used to grouse about the season. He would lock himself in his room to avoid the bustle and good cheer. He heard me sing a snatch (singing snatch?) of It's Beginning to Look a Lot Like Christmas. That launched a loud harangue about the evils and foibles of the hated day, which lasted about fifteen minutes. Since I was a passenger in his car, it was not feasible to walk away. At the end, he turned the radio loud enough to drown any retort. The assault wounded me. For three years I stewed, vacillating between hurt and anger. Finally, I did the only thing I could do: Wrote a story, in which the person was converted, without making him a Christian as a side effect. It gave me surcease, somewhat. But, several years later, I can feel the bruises his words left on me. I last saw the man two years ago. He was busy working out schemes for the government, some of which involved placing sharpshooters at the border, to pick off illegal families as they set foot on our soil. Well, Merry Christmas, ya little sap. Happy New Year.