The 25th of December was originally the Roman festival of Saturnalia. Biblical historians think Christ was born in March. So one could say that Christ-mas has nothing to do with the birth of Jesus. But the Pagan festival was too popular for the incoming Christians to abolish, so they co-opted it.
Saturnalia was once one of the most popular Roman festivals in Europe. It was marked by tomfoolery and reversal of social roles: Slaves and masters ostensibly switched places, much like the Lord of Misrule in later Christian celebrations of the same festival.
Most European Pagan cultures had some sort of midwinter festival. After all, everyone (in cold, dark climates) needs cheering up in winter. So Saturnalia became "Christ's Mass" when Christians persecuted the Pagans. Now that we are entering what is frequently described as the post-Christian era, people still need the midwinter cheering-up.
A Very Buddhist Xmas?
So maybe we need a new name for it. "Winterval"? Whatever we call it, save the trees! Pagans have the winter solstice around December 20-22. Christians party like guilt-ridden Pagans. The ancient Festival of Lights is done in India. Muslims have family get togethers to enjoy. Jews have their annual pilgrimage to Buddhist Chinese restaurants and the movies.
Buddhists, who are always giving gifts, have midwinter Lunar Observance Days. Japanese Buddhists have shopping and KFC. And to American Buddhists of all stripes, it's just a time to shop-sell-produce, promoting consumer-capitalism by all means necessary. Maybe we Americans have the right idea: It's just the "Holiday Season."
What will we do? Loving-kindness (metta) meditation by day to reduce greed, Saturnalia party by night to celebrate Western roots, then tear open some Kris Kringle gifts with loved ones on our national day off (America's bank holiday). But what to call it? The Holidays.