How did Christmas end up on December 25?

No one knows exactly why December 25 was chosen. The Gospels give no date for Jesus's birth, and the earliest undisputed references to a December 25 celebration come from fourth-century Rome. Scholars generally describe two competing explanations: that Christmas replaced or absorbed pagan festivals, and that the date was reached by Christian calculation. The sources below treat the evidence as incomplete and the question as open. [1] [2] [3]

Before the third century most Christians did not celebrate Jesus's birthday, and Origen of Alexandria mocked birthday celebrations as a pagan practice. The earliest surviving reference to December 25 as his birthday is the Chronography of 354, also called the Philocalian Calendar, a Roman calendar made for a wealthy Christian. Its December 25 entry reads that Christ was born in Bethlehem of Judea. A text attributed to Hippolytus also mentions December 25, but it reflects speculation rather than a feast, and its authenticity is disputed. [4] [1]

January 6 may have come first. Around 200 CE Clement of Alexandria reported calculations of Jesus's birth date and a celebration on January 6, later known as Epiphany. That early feast focused more on Jesus's appearance, baptism and divine sonship than on his birth as understood today. [1]

The history-of-religion view holds that Christmas supplanted one or more pagan holidays. HISTORY puts it this way: church officials likely wanted the date to coincide with festivals honoring Saturn and Mithra. The strongest candidate is the Birthday of the Unconquered Sun, established by Emperor Aurelian in 274 CE, which fell on December 25 near the solstice. Supporting this, Augustine told his congregation to honor the day because of the one who made the sun, not the material sun, which suggests that solar imagery was a live concern. A much later marginal note in a 12th-century manuscript also says Christmas was moved from January 6 to December 25 to match Sol Invictus's birthday. [5] [4] [2]

Saturnalia is a weak candidate. Even in its longest form it ended on December 23, and its themes were agricultural renewal and the Golden Age, not the sun. The ABC article goes further and calls a major pre-Christian sun feast on December 25 probably a fantasy, saying the Roman sun cult's festivals fell on other days. Andrew McGowan notes that the earliest Christmas celebrations arose when Christians were not borrowing heavily from pagan traditions. [4] [1]

The second theory, advanced by Louis Duchesne and Thomas Talley, holds that the date was worked out from Easter. It draws on an ancient Jewish idea that prophets died on the anniversary of their conception. Tertullian, writing around 200 CE, gave March 25 as the date of the crucifixion. If Jesus was conceived the same day, a nine-month pregnancy ends on December 25. Another Christian chronicle calculated April 6 for the crucifixion and so reached January 6 for the birth. The writers do not explain their methods, and none links Christmas to Saturnalia. [4] [6]

The two theories need not exclude each other. Historian Walsh, quoted by National Geographic, says the date may have been chosen to coincide with or supplant festivals such as Saturnalia, the birthday of Mithras or Sol Invictus, but that the decision was complex and multifaceted. [4]

The fourth century was decisive for the tradition. Christmas on December 25 took the rest of that century and longer to reach the eastern Mediterranean, where January 6 was already observed. The West in turn adopted January 6, mostly to mark the visit of the Magi, while eastern churches kept it for both baptism and birth. [3] [1]