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Why is christmas on December 25th?

Andrew Henry and Dr. Tom Schmidt dismantle the viral TikTok myth that Christmas was simply a Christian hijacking of a pagan sun god festival, replacing a tired meme with a far more complex historical puzzle involving ancient astronomy and theological math.

The Date Was Not Inevitable

The conversation begins by establishing a hard historical fact that contradicts the idea of a seamless, ancient tradition. Henry notes that in a sermon from 386 AD, the famous Bishop John Chrysostom admits the date is "new for us" and that the church in Rome had only recently adopted it. This admission is crucial because it shatters the assumption that December 25th was the default setting for Christianity from the start. As Henry points out, "Even a big name bishop in a major city like Antioch... the date wasn't settled yet."

Why is christmas on December 25th?

The authors highlight the chaotic "wild west" of early Christian calendar-making, where dates like January 6th, November, and even March 28th were all contenders. This context is vital for the listener; it reveals that the holiday's timing was the result of a long, contested process rather than a single imperial decree or a lazy cultural theft. The evidence suggests that for centuries, the birth of Jesus was a theological abstraction with no fixed anchor in the solar calendar.

The Flawed "Sun God" Theory

The piece then tackles the most persistent theory: that Christians co-opted the feast of Sol Invictus, the unconquered sun god. Henry and Schmidt carefully dissect the evidence, noting that while Emperor Aurelian established a temple to the sun in 274 AD, the specific festival on December 25th appears in the historical record only in the 350s—decades after the Christian date was already gaining traction in Rome.

Henry writes, "The problem with this is that we actually have very little evidence of a Roman festival on December 25th to the sun god." He explains that the earliest calendars do not mention this birth date, and the famous reference by Emperor Julian the Apostate comes too late to prove the pagan festival was the original catalyst. This is a sophisticated correction to the popular narrative. It suggests that the coincidence of dates might be less about one religion stealing from another and more about two different groups observing the same astronomical reality.

Critics might note that the absence of early written evidence does not definitively prove the festival didn't exist in oral tradition, but the authors' reliance on the silence of Roman religious calendars is a strong methodological stance. The argument gains weight when Henry observes that human beings across all cultures naturally mark the winter solstice, making parallel development a plausible explanation.

"It's just very possible that people are noticing the same thing and independently marking these dates in parallel."

The Calculation Hypothesis

The commentary shifts to the more compelling "Calculation Theory," which posits that the date was derived from internal Christian logic rather than external pagan pressure. Henry introduces the world of ancient chronographers—scholars obsessed with calculating the precise dates of biblical events. The core of their argument rests on a specific theological belief: that Jesus was conceived on the same day he died.

Since the crucifixion was tied to Passover, which falls on the 14th of Nisan (often calculated as March 25th in the Roman calendar), early Christians reasoned that the conception also occurred on March 25th. Adding nine months to this date lands squarely on December 25th. Henry explains, "In order to figure out the most important dates in the Christian calendar, which is the crucifixion and resurrection of Jesus, you have to be able to figure out the Passover." This reframes the date not as a compromise with paganism, but as a rigorous attempt to align the birth of Jesus with the cosmic significance of his death.

This theory is elegant because it relies on the internal consistency of Christian theology rather than the shifting sands of Roman politics. It suggests that the date was chosen because it made theological sense to the early church, regardless of what the sun god was doing. The authors effectively argue that the solstice connection is real, but it was likely a secondary reinforcement of a date already chosen for calculation purposes, not the primary cause.

Bottom Line

Henry and Schmidt provide a masterclass in separating historical fact from internet folklore, proving that the origins of Christmas are rooted in complex theological arithmetic rather than simple pagan appropriation. While the "Calculation Theory" offers a compelling internal logic, the biggest vulnerability remains the lack of direct written proof from the earliest centuries, leaving a small window for the pagan influence argument to persist. For the busy reader, the takeaway is clear: history is rarely a story of theft, but rather a messy, fascinating process of calculation and coincidence.

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Why is christmas on December 25th?

by Andrew Henry · Religion For Breakfast · Watch video

Why is Christmas on December 25th? The Bible never gives a date. And every year on social media, you'll hear theories like it was the birthday of the sun god Solen Invictus or Mithris. But the real story is honestly more interesting.

I'm joined by Dr. Tom Schmidt, a Yale trained scholar of early Christianity and the New Testament, who's published research on the origins of Christmas. We're going to walk through all the evidence, the Roman sun god, the winter solstice, and a fascinating Greek inscription carved onto a statue of the Bishop Hippolitus that helps explain how December 25th started to make sense. So with that, let's get into it.

All right. I'm here with Dr. Tom Schmidt. Welcome to the show.

>> Andrew, it's great to be back. >> So tis the season to talk about the date of Christmas. And you have a relatively recent article. I say relatively recent, it was 2015, I believe.

So in the grand scheme of academia, that's recent article on the date of Christmas. December 25th. Why is it on December 25th? I have talked about this on the channel before about the history of religion thesis and the calculation thesis.

And I want us to walk the audience through all the arguments for why we think early Christians largely settled on December 25th. And we can get into why I use the word largely there too. so maybe start us off where you think makes the most sense. I think maybe what makes the most sense is starting with the more certain data that we have because in so much historical investigation there's a lot that's squishy and unclear.

So maybe we'll start with what is clear and what everybody agrees on and then we'll we'll go from there. what everyone agrees on is that in 386 AD, John Chrysstm, John Chrysstm is a very famous Christian figure. he's the bishop of Antioch in 386 and he's preaching a Christmas sermon that we have and it's on December 25th and in it he says, folks, this date is new for us. We just started celebrating this date less than 10 years ago, he says.

So that brings us back to 376. And he says, and actually this date is spreading throughout the whole Roman world right now, the Roman Empire right now. And we know that he's right about ...