Why is Christmas on December 25?
Nobody knows for sure. The Bible gives no date, and the earliest record of December 25 as Christ’s birthday is a Roman calendar from 354. Historians weigh two main explanations, and neither is proven.
Quick Answer
The Bible doesn’t give a date for Jesus’ birth, and historians don’t know exactly why Christmas ended up on December 25. The earliest surviving reference is the Chronography of 354, a Roman calendar compiled by Furius Dionysius Filocalus, which lists December 25 as the day “Christ was born in Bethlehem of Judea.” It appears to rely on a list that goes back to about 336. Two explanations are debated. One is a calculation: the 3rd-century Christian writer Sextus Julius Africanus linked March 25 to Jesus’ conception, and nine months after March 25 is December 25. The other is a Roman festival: in 274, Emperor Aurelian established a feast for the birthday of the Unconquered Sun (Sol Invictus), and some scholars think Christians chose the same date. But the earliest evidence that the sun festival fell on December 25 is the same 354 calendar, so it’s unclear which came first. By the 4th century, December 25 was the dominant date in the Western church.
By the Numbers
Key Facts
- The Bible
- Doesn’t give a date for Jesus’ birth
- Earliest record
- The Chronography of 354, a Roman calendar listing December 25 as Christ’s birth
- Leading ideas
- A calculation from March 25, or a link to a Roman sun festival
- Status
- Debated by historians; neither idea is proven
Two ideas about the date
| The calculation idea | The Roman festival idea | |
|---|---|---|
| The idea | Early Christians linked March 25 to Jesus’ conception, so his birth fell nine months later, on December 25. | Christians chose December 25 to match, or compete with, the festival of the Unconquered Sun. |
| Earliest evidence | In the 3rd century, Sextus Julius Africanus tied March 25 to the conception. | Aurelian founded the sun festival in 274, but its December 25 date first appears in the 354 calendar. |
| The limit | It shows how the date could have been worked out, not that Rome did so. | There’s no direct evidence the festival fell on December 25 before the 354 calendar, so it may not have come first. |
Sources: Britannica, National Geographic and the Biblical Archaeology Society. Historians continue to debate both ideas.
The Bible doesn’t say
The Gospels don’t give a date for Jesus’ birth. Their writers were telling a theological story rather than keeping a calendar. The earliest surviving record that names December 25 is the Chronography of 354, an illuminated Roman calendar compiled by Furius Dionysius Filocalus. It notes, under December 25: “Christ was born in Bethlehem of Judea.” The calendar appears to draw on a list that goes back to about 336.
The calculation idea
The 3rd-century Christian writer Sextus Julius Africanus connected March 25, which the Romans reckoned as the spring equinox, with the creation of the world and with Jesus’ conception. Count nine months from March 25 and you arrive at December 25. Some scholars see that reasoning as the source of the date.
The sun festival idea
In 274, Emperor Aurelian established a feast for the birth of Sol Invictus, the Unconquered Sun. Since the 18th and 19th centuries, many scholars have argued that Christians picked December 25 to compete with or absorb that festival. The catch is that the earliest evidence for the sun festival on December 25 is the same 354 calendar that lists Christmas, so it’s hard to say which came first. Saturnalia, the Roman festival often named in this story, ended on December 23 even in its longest form.
Myth vs. Fact
MythChristmas was invented to replace Saturnalia.
FactSaturnalia ended by December 23, even in its longest form. The debate historians have is about a sun festival, and the evidence doesn’t settle it.
MythDecember 25 is Jesus’ known birthday.
FactThe Bible gives no date, and historians don’t know the day. December 25 is the date the Western church had settled on by the 4th century.
The Bottom Line
Christmas is on December 25 because the Western church settled on that date by the 4th century, but why that date is uncertain. Two ideas, a nine-month calculation from March 25 and a Roman sun festival, are still debated.