Around Christmas those who profess to care not about religion love to extoll their pathological zeal that Christ wasn’t born on the 25th – are they correct?
In a word: no. Christmas isn’t just some reappropriated pagan Saturnalia/Sol Invictus/Horus/Mithras/*insert generic pagan god* celebration as purported by pop internet historians quoting articles featuring poppycock no-name professors or “best-seller” authors that wish to undermine all that the Church is founded on. Instead, we see from ancient sources definitive proof that December 25th is the true date for the Nativity of Christ.
The earliest source for the December 25th dating comes from Saint Hippolytus of Rome in his Commentary on Daniel written around the year 205 A.D., just barely two hundred years after the Birth of Christ.
“For the first advent of our Lord in the flesh, when he was born in Bethlehem, eight days before the Kalends of January [December 25], the fourth day [Wednesday], while Augustus was in his forty-second year, but from Adam, five thousand and five hundred years. He suffered in the thirty-third year, eight days before the Kalends of April [March 25], the day of preparation [Friday] the eighteenth year of Tiberius Caesar, while Rufus and Roubellion were Consuls.”
150 years laters comes the next earliest mention of the date comes in the Chronography of 354, produced by Roman calligrapher Filocalus for a wealthy Roman Catholic named Valentinus. The calendar has a section entitled Item Depositio Martirum – a list dating martyrs lives.
It’s first line is: “VIII kal. Ian. natus Christus in Betleem Iudeae.” Translated, it means “Eighth day before the kalends of January [December 25] Birth of Christ in Bethlehem Judea,” corroborating the account of Saint Hippolytus.
The Chronography also has a list of Roman consuls to 354 A.D. The section listing Caesare and Paulo at 1 A.D. has a subtext: “Hoc cons. dominus Iesus Christus natus est VIII kal. Ian. d. Ven. luna xv.”
“When these [Caesare and Paulo] were consuls, Lord Jesus Christ was born 8 days before the kalends of January [December 25] on the day of Venus Moon 15.”
About thirty years later in 386 A.D., Saint John Chrysostom writes a homily in which he appeals to the now-lost to history Roman census records. He writes that Christ’s birthday has always been celebrated as the 25th of December.
“The 25th day of December has been celebrated from the beginning as the birthday of Christ, and the knowledge of it is now transmitted to us. It is manifest from Scripture that Christ was born at the enrollment or census, and the very day was certain from a written document in the Roman archives. It is lawful for anyone to search these ancient records, publicly deposited at Rome, and there to learn the time of this enrollment.”
The date wasn’t localized to just the Holy Land and its surrounding area. In 400 A.D., the date was firmly established in Africa. Saint Augustine of Hippo in his Treatise on the Trinity writes:
“For He is believed to have been conceived on the 25th of March, upon which day also He suffered; so the womb of the Virgin, in which He was conceived, where no one of mortals was begotten, corresponds to the new grave in which He was buried, wherein was never man laid, neither before nor since. But He was born, according to tradition, upon December the 25th.”
It’s clear from a cursory overview of historical sources by anyone with a modicum of sincerity that the date of Christmas as December 25th stretches well back into antiquity, and is not whatsoever a day superimposed on pagan celebrations.