Around this time of year we often hear about the "common knowledge" that the date of Christmas was in fact based on the date of a Pagan feast to do a sort of holiday one-upmanship. I have already heard this at least once this year during a television drama and often heard it from my Uncle as I was growing up.
Even in Catholic circles we often hear about Pagan holidays and practices being "baptized." Mostly we hear about this in regards to All Saints Day and Christmas. The facts are otherwise and what is not true about All Saints Day is also not true about the date of Christmas. Last year Mark Shea posted a section from his upcoming book on Mary.
Time was when I, like most people, took it for granted the winter solstice and, in particular, the Roman Feast of the Birth of the Unconquered Sun were simply pagan celebrations that hung around into Christian times. In fact, when I set out to write this book I still thought this. But I discovered the reality is far more complicated and interesting. Indeed, it turns out this widely assumed “fact” that “everybody knows” is probably another sample of pseudo-knowledge. For according to William Tighe, a church history specialist at Pennsylvania’s Muhlenberg College, “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.”
For the fact is, our records of a tradition associating Jesus’ birth with December 25 are decades older than any records concerning a pagan feast on that day.
[T]he definitive “Handbook of Biblical Chronology” by professor Jack Finegan (Hendrickson, 1998 revised edition) cites an important reference in the “Chronicle” written by Hippolytus of Rome three decades before Aurelian launched his festival. Hippolytus said Jesus’ birth “took place eight days before the kalends of January,” that is, Dec. 25.
Tighe said there’s evidence that as early as the second and third centuries, Christians sought to fix the birth date to help determine the time of Jesus’ death and resurrection for the liturgical calendarlong before Christmas also became a festival.
Read the rest of his informative post to find out why originally the early Christians had determined that Dec 25th was the date of our Savior’s birth.