Why Is Christmas Celebrated on December 25?

When Is Jesus’ Real Birthday?

First of all, no one can say with certainty precisely when Jesus was actually born. Many scholars believe he most likely wasn’t born on December 25, and in fact may have been a spring baby. The Bible does not mention a specific day, month, or year for his birth.

The timing of Christmas is further complicated by the discrepancies between the Julian and Gregorian calendars, which is why Christmas isn't universally celebrated on December 25. January 6 is the preferred date for Armenian Apostolics, while most Oriental and Eastern Orthodox churches observe it on January 7.

Is the Date of Christmas Based on the Winter Solstice?

One of the most widely accepted theories for the date of Christmas involves the winter solstice, which in ancient Rome took place on December 25. According to the fourth-century theologian Augustine of Hippo, Jesus chose to be born on the shortest day of the year: "Hence it is that He was born on the day which is the shortest in our earthly reckoning and from which subsequent days begin to increase in length. He, therefore, who bent low and lifted us up chose the shortest day, yet the one whence light begins to increase." This interpretation was later supported by Isaac Newton.

The December 25 date may also have been chosen by the Roman Catholic Church in an attempt to co-opt the pagan festival of Saturnalia, which was dedicated to the Roman deity Saturn.

Is the Date of Christmas Based on Passover?

The earliest theologians who discussed Jesus’ birthday mentioned that he was likely divinely conceived during Passover, the Jewish holiday on which he was also later crucified. They calculated Passover in the year of Jesus’ death as March 25, and arrived at December 25 (nine months later) as a likely date for his birth. Eastern Christian communities used a different calendar, which calculated the date of Passover as April 6; that’s how we got January 6 as Christmas in some parts of the world.

Another theory centers more specifically around the Annunciation, or the day that the Archangel Gabriel told Mary she would give birth to the Son of God. The Annunciation is observed on March 25 — again, exactly nine months before December 25.

When Did Christmas Start Being Celebrated on December 25?

Whatever the case, Christmas taking place on December 25 is hardly a new phenomenon. Christmas probably started being commemorated around the second century, and the church decreed that it be held on December 25 in 336 CE. However, Christmas did not become a really significant Christian holiday until the ninth century. In the end, some theologians argue that the precise date of the celebration doesn’t matter a great deal, as long as the spirit of the day is preserved.