Or do we celebrate Christmas then because of the pagans?

Here’s a thought for the harried among us who are unready for the arrival of another Christmas season: There was a time when some scholars argued that the holiday should be observed in the spring. Just imagine three more months of shopping!

It seems to us a matter of course that Christmas should come on Dec. 25. But over the past 2,000 years or so, the timing of Jesus’ birth—which, as the bumper stickers like to remind us, is the original reason for the season—has generated considerable controversy. In fact, there has been enough uncertainty about when to celebrate Jesus’ birthday that some Christians have chosen not to celebrate it at all.

The Bible offers little help in resolving the question: No dates are offered in the Gospel stories. There isn’t even a reference to the season of the year. Some readers have thought they detected a clue in the evangelist Luke’s mention of shepherds tending their flocks at night as they hear the news of Jesus’ birth. To some, this suggests not a December birth, but one during the spring lambing season, when the animals would be free to roam out of their corrals. But wait: Advocates for a December Nativity answer that sheep reserved for temple sacrifices would have grazed unfettered even in deepest winter.

Clearly, any dispute that hinges on knowledge of Middle Eastern livestock practices of antiquity is not going to be resolved easily.

Why should it matter? The earliest Christian writers were more interested in Jesus’ death and resurrection than in his birth. The oldest of the Gospels, Mark’s, makes no mention of Jesus’ birth. Later, Matthew and Luke offered extravagant detail—stars, wise men, mangers—but no specifics about timing.

This didn’t stop others from making their own guesses. The theologian Clement of Alexandria, writing around 200, mentions some of the dates that had by then already been proposed as the true date of Jesus’ birth. Spring Nativities were popular, with dates in May, April, and March being proposed. Dec. 25 is not mentioned as a possibility.

So how did we end up celebrating a wintry white Christmas? The church only settled on a Dec. 25 Christmas in the fourth century. The standard explanation is that the early church conflated its celebration of the Nativity with pre-existing pagan festivals. Romans had their Saturnalia, the ancient winter festival, and northern European people had their own solstice traditions. Among the features: parties, gift-giving, dwellings decorated with greenery.

The reasoning goes that the growing church, recognizing the popularity of the winter festivals, attached its own Christmas celebration to encourage the spread of Christianity. Business historian John Steele Gordon has described the December dating of the Nativity as a kind of ancient-world marketing ploy.