Why Is Christmas on December 25? How the Early Church Chose It

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Christmas falls on 25 December because the early church chose that day to keep the birth of Jesus. The Bible gives no date. Rome was keeping the feast probably by 336, and historians give two explanations for the choice: a reckoning nine months on from 25 March, and a Roman feast of the Unconquered on the same day.

The Christians of the fourth century knew that their neighbours kept 25 December too. The Roman calendar of 354 marks the day N. Invicti, the birthday of the Unconquered, with thirty chariot races. An early sermon, On Solstices and Equinoxes, once printed among the works of John Chrysostom, takes up the pagan name and answers it, though no one knows for certain when or where it was preached. They call it “the Birthday of the Unconquered”, the preacher says, and he asks, “Who indeed is so unconquered as Our Lord?” Then he reaches for a title from the prophet Malachi: “Or, if they say that it is the birthday of the Sun, He is the Sun of Justice.” Malachi had promised that “unto you that fear my name shall the Sun of righteousness arise with healing in his wings” (Malachi 4:2). Rome was racing chariots for the Sun in the shortest days of the year, and a Christian preacher looked at the same sky and named the one who rises with healing.

It may surprise us that for most of their first three centuries Christians kept no birthday for Christ at all. Their great feast was Easter, the Gospels themselves tell us far more about the days of his death than about the day of his birth, and Irenaeus and Tertullian, who wrote about so much else, never mention a feast of his birth. Christians did wonder about the date, all the same. About AD 200 Clement of Alexandria wrote down guesses that fell in April and May, and in 243 a treatise falsely credited to Cyprian put the birth on 28 March, the day on which it believed God had made the sun. So a Christian was already setting the birth of Christ beside the making of the sun, a century before Rome’s calendar of 354.

That calendar gives us the oldest record of the feast on 25 December. It is a book of calendars made in Rome in AD 354, and one of its lists gives the days on which the Roman church remembered its martyrs, the men and women who had died for Christ. Before any martyr is named, the list opens with VIII kal. Ian. natus Christus in Betleem Iudeae, “Christ was born in Bethlehem of Judea”, on the eighth day before the kalends of January. A church that kept the death-days of its witnesses began its list with a birth, the one birth that gave every one of those deaths its meaning. The list was probably drawn up about 336, though the Christmas line may have been added later, so we can say that Rome kept the feast probably by 336 and certainly by 354.

There is a hint that Africa knew the date earlier still, and it comes to us through a quarrel. Augustine, writing about 400, mentions the Donatists, North African Christians who had broken away from the rest of the Church about 311 or 312. They apparently kept 25 December and refused the newer feast of 6 January, and a group that had split away and clung to the customs of its own day would hardly have taken up a new Catholic feast afterwards. It seems, then, that the Christians of Africa were keeping Christ’s birth on 25 December before the split, and a sad division in the Church has kept that memory for us.

No one in the ancient Church left us a note saying who chose the day or why, so historians work from the clues. They have two main explanations, each with an objection to answer. The historian Philipp Nothaft, who has surveyed the whole debate, thinks the two can no longer be set against each other as sharp alternatives.

Nine months after 25 March

The first explanation starts at the cross. About AD 200 Tertullian of Carthage dated the crucifixion “on the eighth day before the calends of April”, which is 25 March. Many early Christians held that Christ was conceived on the same day of the year that he died, so that his saving work began and ended on one date, and nine months on from 25 March brings us to 25 December. Augustine sets it down in On the Trinity: “For He is believed to have been conceived on the 25th of March, upon which day also He suffered.” And then, “But He was born, according to tradition, upon December the 25th.” So the Christians who reckoned this way could not look at the child without seeing the cross, because to them the day he was conceived in Mary’s womb was the day he would die.

Christians in the East made the same reckoning from a different day. They placed the passion on 6 April in their local calendar, and nine months on from that is 6 January, which became their feast of the birth. East and West kept different calendars and shared one conviction, that the child in Mary’s womb already carried the cross.

No writer of those years, though, says that the date of Christmas was worked out this way. The sermon on the solstices does the sum, but no one knows when or where it was written, and it may be explaining a date chosen for other reasons. Nothaft still thinks the calculation deserves more weight than it has been given, because from the third century on Christian scholars built careful systems of dates around Christ’s conception, birth and death. They cared enough about the days of his life to reckon them, and their reckoning may lie closer to the root of Christmas than many have allowed.

The Roman feast of the Unconquered

For the second explanation we turn to the Roman calendar and to the emperor Aurelian, who dedicated a temple to the Sun in Rome and founded games in the god’s honour; historians usually date his new feast of the Sun to 274. The same book of 354 that records Christ’s birth gives 25 December to the Sun. Those who favour this explanation hold that Aurelian set the Sun’s feast on that day and that the Church then put Christmas beside it, to give the people a Christian feast in place of a pagan one. If it happened that way, it was a bold thing to do, to take the empire’s own festival of the Sun and give the day to Christ.

When the archaeologist Steven Hijmans gathered the Sun’s other known festivals, in work Nothaft summarises, he found them on 8 or 9 August, 28 August, 19 or 22 October and 11 December, and none of them at the winter solstice. The calendar of 354 is the earliest source we have for a festival of the Sun on 25 December, and it is the very book that gives us the earliest record of Christmas. The two birthdays come into the record together, and no one can say which was kept first; it is even possible that the Sun’s feast was set there in answer to the Christians. If you have read that Christmas is simply the Sun’s feast renamed, this is what that claim leaves out. No Christian writer of those centuries says the date was chosen to match a pagan feast, and the first to say so is a note in the margin of a manuscript of Dionysius bar Salibi, a Syriac writer of the twelfth century, some eight hundred years after Rome first kept the feast.

Two other stories are told often enough to deserve an answer. You may have heard that the emperor Constantine turned the Sun’s feast into Christmas, but there is no evidence for it, and Constantinople, the city he founded as his capital in 330, did not keep Christmas until 379 or 380. The Saturnalia is blamed even more often, yet the calendar of 354 sets it on 17 December, eight days before Christmas, and it did not fall on the 25th. The wider charge, that Christmas took over the Saturnalia, Yule and the greenery, is weighed in whether Christmas has pagan origins.

We do know how the Christians who noticed the Sun’s feast spoke about it, and they did not apologise. Ambrose of Milan called Christ the true sun, who outshone the fallen gods of the old order, and the preacher of the solstice sermon turned the pagan title into praise. They were sure enough of Christ to let the Sun’s birthday point to him, and we can share their confidence.

The faith those Christians confessed in the shortest days of the year, and handed on to us, is the subject of our free course, Christianity: What Christians Have Believed for 2,000 Years.

We do not know the day. The Gospels give no date, and most historians place the birth in 4 BC or a little before, about 6 to 4 BC, while Herod the Great was still alive. The reasons are set out in when Jesus was born. Some early Christians hoped a record had survived, and John Chrysostom told his people that the census papers of the Holy Family were still kept in Rome, though he had never been there himself. No such paper has come down to us. The evangelists who tell us about the shepherds and the star do not tell us the day, and the Church has kept the birth since the fourth century without knowing it.

In the East, 6 January was already a great feast, the day many Christians kept Christ’s appearing and remembered his birth and his baptism together, and the December date came to them slowly. Gregory of Nazianzus began the December feast in Constantinople in 379 or 380. At Antioch, almost certainly in 386, John Chrysostom defended it before a crowded church. He had long wanted the feast brought to Antioch, he told them, though conservatives had always resisted it, and part of his congregation had already kept it for at least ten years. In the West, he claimed, it had been kept “from the beginning”, and from Thrace to Cadiz. So some of the Christians of Antioch were keeping Christmas for a decade before their whole church did, and Chrysostom stood up to bring the rest of them along.

Egypt took up the feast between 427 and 433, and Jerusalem held to its own way longest. A pilgrim named Egeria, who was there in 385, found the birth celebrated in January, with the bishop going out to Bethlehem each night and returning to Jerusalem for the day. There is something lovely in that picture, a bishop keeping the birth by night in the town where it happened and coming home with the morning. As late as the middle of the sixth century, Jerusalem still kept the birth and the baptism as one feast.

Where the two dates met, the Church kept both. 25 December became Christmas, 6 January became the feast of the Epiphany, and the days between became the twelve days of Christmas. The twelve days we keep are the meeting of West and East, two old ways of keeping one birth, joined into a single season.

Because they keep the old Julian calendar, which now runs thirteen days behind the one most of the world uses. The Russian Church, among others, still keeps its feasts by it. Their Christmas is still 25 December, and that 25 December falls on what the rest of us call 7 January. Many other Orthodox churches use the corrected calendar and keep Christmas on 25 December with Western Christians. An Orthodox priest in America, Lawrence Farley, notes how often people are told that the Orthodox “celebrate Christmas on January 7, thirteen days later than Christians of the West”, when in truth they keep the same feast by a different calendar. So Christians on both calendars keep the birth on the same 25 December, and only the calendar on the wall puts them thirteen days apart. The Armenian Apostolic Church keeps the older Eastern custom and celebrates the Nativity and Theophany of Christ together on 6 January, as Jerusalem still did in Egeria’s day.

The early Christians kept the feast to honour the Word made flesh, and they set it in the darkest week of the Roman year. Ever since, that week has been the time the Church sings of the light, and we still gather in it.

Long before there was a feast on any date, Zacharias sang over his newborn son John of the child who was coming: “the dayspring from on high hath visited us, To give light to them that sit in darkness and in the shadow of death, to guide our feet into the way of peace” (Luke 1:78–79).

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• When was Jesus born?
• Is Christmas pagan?
• When are the 12 days of Christmas?
• Why do Christians celebrate Epiphany?
• What is the origin of Christmas Eve?

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