Why Christmas Day is Christmas Day

The seasons, festivals, historians and emperors have all influenced the date of Christmas.

Ryan Gilfeather

Ryan Gilfeather explores social issues through the lens of philosophy, theology, and history. He is a Research Associate at the Joseph Centre for Dignified Work.

a had holds out a small wrapped Christmas present.

I came of age in the 2000s, a decade quite alien to us now. We saw ourselves as pioneers of technology, as the internet emerged in its prehistoric form. There was great optimism about the economy until it all went wrong in 2008. The New Atheism movement was roaring into public view, only to wane just as quickly the decade after. Growing up as a Christian, I remember spirited debates with my peers about whether science disproved Christianity and if God can be disproven. These questions have fallen out of view, just as many of its main proponents have too. Richard Dawkins rarely darkens the door of our TV screens anymore.

However, one such moment of conflict sticks out in my mind. A friend announced to me that he had disproved the origins of Christianity. The night before he had discovered that in the third century Roman Empire, before Christianity became legal and the official religion, there was already a festival celebrating a god on the 25th of December. Instead of the birth of the Son of God, the Romans celebrated the rebirth of the Unconquered Sun — Sol Invictus. Then, in 336 under the first Christian Emperor, Constantine, that date was first celebrated as the day of the birth of Christ. My friend considered the case to be closed; surely the birth of Christ was merely a repurposing of an existing festival?

Thankfully this shocking revelation did not pick away at the foundations of my faith. I continued, and still continue, to believe in and love the Christian God, as revealed in the Bible. Indeed, since that moment I have trained as a scholar in the history of the early Church, and have begun to see this question for what it is, a quirk of history.

We, therefore, celebrate Christ’s birth on the 25th December on account of a quirk of history, a result of the way that Romans mapped significant events on to the waxing and waning of the light.

The first claim that Christ was born on the 25th December appears in the third century. Sextus Julius Africanus, a Roman Christian historian, wrote an entire chronology of the world from creation to AD 221. He considered March 25th to be the date of creation, because it was the spring equinox in the Roman Calendar, a day which represents new life and new birth. For this reason, he likewise considered it to be the date of Christ’s conception in the womb. Crucially, nine months after that falls December 25th. Although I admire his logic, it is hardly a sound basis for establishing the date of our Lord’s birth. Indeed, other Christians didn’t accept this claim at the time either.

As already mentioned, December 25th was a significant date in the Roman calendar already. It was the winter solstice, the shortest day of the year, after which the days begin to lengthen. It also shortly followed the popular Roman festival of the Saturnalia. Already endowed with significance, it is unsurprising that the Romans began to celebrate the rebirth of Sol Invictus, and the birth of another god, Mithras, on that date.

At this time Christianity was an illegal religion, persecuted in some parts of the Roman Empire. However, in 312, the emperor Constantine converts to Christianity and in 313 makes it a legally tolerated religion. At this point he begins to invest the church and Christians with powers, wealth and privileges. Evidence from the Chronography of AD 354 suggests that Christmas was first celebrated on the 25th December in 336, during the reign of Constantine. Perhaps this was an attempt to dislodge existing pagan holidays, and replace it with a Christian one. Or, maybe the significance of the Winter solstice made that date most plausible. Indeed, it is easy to see how the commemoration of Christ coming into the world is particularly salient as the darkness begins to recede. The true answer is, of course, lost to history.

We, therefore, celebrate Christ’s birth on the 25th December on account of a quirk of history, a result of the way that Romans mapped significant events on to the waxing and waning of the light. The true lesson here though, is that it simply doesn’t matter what the actual date of Christ’s birth was. Our records, and those available in the early church were simply not good enough for us to ever know. What matters is that God loves us so much, that he became human to bring us back to his side in everlasting joy and peace. We have no idea on what date Christ was born. But, each year the 25th December presents a time for us to remember that God became man, so that we might have everlasting life.

Review

Belief

Books

Culture

28 May 2025

4 min read

Could Lamorna Ash become a Christian in a year?

Moving, funny and beautifully written, this young writer’s quest for faith has lessons for all of us.

Lucy Denyer

Lucy is a writer and editor.

Lamorna Ash.

When two of Lamorna Ash’s university friends decided to leave behind their lives as standup comedians and train to become priests, Ash was fascinated. She interviewed them and wrote an essay about it for the Guardian but, by the time her piece came out, knew she was “not finished with Christianity.”

“Perhaps it was naive not to have anticipated how spending my days alongside two fresh converts… would have some cumulative effect on me,” she writes. “Through these encounters, it was as if the very corner of the sky had been pulled back. I couldn’t see what was going on behind it, but I understood it was there for them… they taught me how to believe in the belief of others… their stories became the starting point.”

And so Ash bought a second hand Toyota Corolla, stocked the glove box with CDs and set off on a Christian road-trip around the country that started with a Christianity Explored course and ended with a series of meetings with people who were consciously ‘dechurching’, taking in Catholics, Orthodox Christians, Quakers, Anabaptists and a YWAM community along the way. She books in ‘desert times’ on Iona; in Walsingham; at a silent Jesuit retreat. She walks, and talks, and tries to pray and thinks. Throughout her travels, Ash carried a ‘jokey’ question in the back of her mind to frame her research: could she become a Christian in a year?

The result of her quest is this book: tender, fascinating, moving, funny and beautifully written. Throughout my reading of Don’t Forget We’re Here Forever I kept thinking of people I would like to give it to, Christian and non-Christian alike. Ash has achieved a remarkable feat: to make faith and its pursuit a compelling subject regardless of whether you’re a believer or not.

Primarily, this is because she has not - joke question aside - set out with an agenda, other than to more fully understand what makes believers tick (and, she admits, because it is something to write about). Though she is scathing about Rico Tice, whom she finds performative and evasive, and finds the dogma of the Christianity Explored course too rigid and inflexible for her liking, she is sympathetic towards and interested in her fellow Christianity Explored small group companions - and is self-aware enough to admit that during this time she “played the worst version of myself: hackles raised, on alert, unable to let a conversation pass without some interjection”. Though she finds the intensity of Youth With A Mission’s community - along with the fact that many of the staff are married to each other - a bit much, she is individually drawn to some of the people who work there, and reflective about what and why they’re doing. As someone who has grown up with faith, it is fascinating to see what we often take for granted held up to scrutiny by someone who is not there to be deliberately combative, but to try and understand.

“I am still too close to it to tell you definitively all the ways the encounters… changed me,” Ash writes. “What it felt like at the time, though, was that each conversation was leading me to places in my own mind I had never visited before.”

There are elements of Ash’s book I am intrigued by, but sceptical of: her suggestion, for example, that the Bible should not stop where it does, but might be continually added to, “like a divine Wikipedia, updated in perpetuity.” Her theological understanding is not, perhaps understandably, advanced. She is a self-confessed product of her era: young, progressive, queer, and her readings of and understandings of other people are framed through that lens.

But despite its failings, Don’t Forget We’re Here Forever remains compelling because of its curiosity - a curiosity that Ash wonders might be the place “where God exists”; its attempts, however stumbling, to understand faith rather than just dismiss it. It is an atheist Quaker who teaches Ash “how I might approach Christianity: it was supposed to be a challenge.” You will have to read it to learn where Ash herself ends up, but her book extends the challenge to those of us who might benefit from a similar scrutiny of what we believe - not to fall out of faith, but also to understand it, and God, more.

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