The way it was explained to me is this.
in an agricultural society, there comes a point in the year when you have to decide what livestock you can feed through the winter and what you have to slaughter. The known event at this time is the winter solstice. If you use that then it keeps your yearly routine constant. Now there is only so much meat that you can preserve so you have a feast with the rest.
When I celebrate Christmas, it is touching base with all our ancestors that sat around the fire in days of yore.

I celebrate Bosquevus.

Bosquevus photos

Bosquevus is celebrated From the Winter Solstice until New Years. It combines the winter solstice, saturnalia, Hanukkah, Christmas, KWANZAA, and festivus.