Why is Christmas on December 25? Did Christians make use of a pagan festival date when they decided to celebrate Christ’s birth? Very unlikely, as you will understand if you read William J. Tighe’s  “Calculating Christmas.”

“In the Julian calendar, created in 45 B.C. under Julius Caesar, the winter solstice fell on December 25th, and it therefore seemed obvious [to some] that the day must have had a pagan significance before it had a Christian one. But in fact, the date had no religious significance in the Roman pagan festal calendar before Aurelian’s time, nor did the cult of the sun play a prominent role in Rome before him.

“There were two temples of the sun in Rome, one of which (maintained by the clan into which Aurelian was born or adopted) celebrated its dedication festival on August 9th, the other of which celebrated its dedication festival on August 28th. But both of these cults fell into neglect in the second century, when eastern cults of the sun, such as Mithraism, began to win a following in Rome. And in any case, none of these cults, old or new, had festivals associated with solstices or equinoxes.”

Tighe explains that “…the pagan festival of the ‘Birth of the Unconquered Sun’ instituted by the Roman Emperor Aurelian on 25 December 274, was almost certainly an attempt to create a pagan alternative to a date that was already of some significance to Roman Christians. Thus the ‘pagan origins of Christmas’ is a myth without historical substance.”

If they didn’t choose December 25 for that reason, why did they? For reasons we never would have thought of in modern times. Read the whole brief article to find out.