The Christmas season often leads to many questions about the historicity of events surrounding the birth of Jesus. In this post, I would like to survey the historical evidence for the celebration of Christmas and the establishment of its date which did not necessarily happen at the same time. It may be surprising to learn that the Eastern and Western Churches initially recognized Christ’s birthday on different days! But in both regions of the church, the feast of Christmas only began to be celebrated in the fourth century.

Christmas was not immediately seen as important to the earliest Christians as Easter was. Debates about the date of Easter ran throughout the second century. Some in the early church celebrated Jesus’s resurrection on the first Sunday after Passover (based on New Testament gospel accounts) while others focused on the death of Jesus and celebrated it on the night of Passover, whatever day of the week it occurred.

The earliest evidence for dating the birth of Christ by members of the Eastern Church (going clockwise around the Mediterranean from Greece to Asia Minor, Syria, Palestine and Egypt) can be traced to the second century as well. Christian theologian Clement of Alexandria, Egypt (c. 150-215), believed that Jesus was born on November 18 in 3 BC (more about how Christ can be born “before Christ” later). In his book Stromata (“Miscellanies”) Clement also noted that followers of the Gnostic heretic Basilides chose May 20 as Jesus’s birthday. As we will see below, Clement may have confused the Basilidean’s reckoning of Jesus’s conception (the incarnation) with that of his birth.

Epiphanius, the fourth-century bishop of Salamis on the island of Cyprus, wrote in his book Panarion (“Medicine Chest”) that a group of heretics called the Alogoi (“anti-logos”), opponents of the theology expressed in the Gospel of John, thought that Jesus was born in the year equivalent to 9 AD! Nevertheless, they dated Mary’s conception to either June 20 or May 21, the latter in agreement with the date given by the followers of Basilides for Jesus’s birth according to Clement but probably misunderstood as the date of his incarnation. Epiphanius himself accepted June 20 as the date of Mary’s conception. To arrive at the date for Christmas, he followed a tradition in which it was said that Mary’s pregnancy lasted seven lunar months less four days (202 days). An inclusive count results in Jesus’s birth being on January 6, the most popular date in the East for this event. Epiphanius accepted the year of Jesus’s birth as equivalent to 3/2 BC.

The Christian theologians of the western church (going clockwise around the Mediterranean from North Africa to Spain, Gaul, and Italy) also accepted the year of Jesus’ birth as 3/2 BC (Irenaeus, Tertullian, Origen, Eusebius). The Christian-generated Roman City Calendar (Chronograph) of 354 AD (probably reflecting the situation from as early as 336) gave the accepted birth date of Christ as December 25.

Future Eastern bishop of Constantinople, John Chrysostom, wrote in 386 that within the previous ten years, his church and others in the East had begun to follow the Western dating of Christmas as December 25. He supported his conclusion based on details he derived from the Gospel of Luke, chapter 1.

Chrysostom misinterpreted Luke 1:9 as indicating that Zechariah, the father of John the Baptist, was the Jewish high priest at the time of the announcement of John’s conception. This was because only the high priest could enter the Holy of Holies, the innermost and holiest part of the Jerusalem Temple. This entry could only be done on the Day of Atonement (Tishri 10; see Lev. 16, Num. 15:25, Heb. 9:7). Since Zechariah “had entered the temple of the Lord” when the angel announced John’s conception, Chrysostom concluded that Zechariah was the high priest and that Tishri 10 was the date of John’s conception. (In Chrysostom’s time, Tishri 10 fell on September 20.) Six months later, according to Luke 1:26, Mary received an angelic announcement that she would conceive. Chrysostom resolved that she had conceived the following month (April). Counting nine months out, inclusive of April, he affirmed that the month of Jesus’s birth was December. This was enough for Chrysostom to accept December 25 rather than January 6 as Jesus’s birth date.

Both dates, December 25 and January 6, were important in the ancient world. Both were variously given as dates of the winter solstice, the time when “the sun stands still” and the days begin to grow longer (today the solstice is calculated as December 21). Important pagan festivals were celebrated on these dates including Isis festivals in Rome. In Egypt, on January 5/6, a ceremony was held to mark the day of Kore, the virgin, who gave birth to Aion, a Hellenistic deity associated with time. Similar ceremonies were held at Petra and Elusa in Arabia according to Epiphanius. December 25, on the other hand, was the date of the pagan festival honoring Deus Sol Invictus (“the Unconquered God of the Sun”) who had been the official deity of the Roman empire since 274 AD. There were even Biblical allusions to the Messiah arising during the solstice according to some.  Malachi writes (4:2), “And for you who fear my name a sun of righteousness shall rise, and healing is in its wings.” As the December date gained supremacy throughout the Christian church, the January date, called the Epiphany, was kept to honor the coming of the magi, that is, the “manifestation” of Christ to the Gentiles, among other things.

Back to the question of how Christ came to be born “before Christ” (BC). This difficulty began with the method by which time was calculated in the ancient Roman world. In Jesus’s time and place, dates were reckoned with respect to the founding of Rome. The death of Herod the Great, for example, was recorded as occurring in 750 AUC (Anno Urbis Conditae = “from the founding of the city” of Rome). The year is equivalent by our modern reckoning to 4 BC. According to the Gospel of Matthew 2:16, Herod began looking to kill infants in Bethlehem who had been born within the previous two years (obviously, before Herod’s death). Thus, Jesus is reckoned by most scholars to have been born about 748 AUC (6 BC). But that still doesn’t answer the question of how Jesus came to be born “BC”.

After the advent of the Roman Emperor Constantine (r. 324-337), many Christians began to calculate time from the date of the greatest persecution to have ever been launched against them. This occurred under the former Emperor Diocletian who was crowned emperor on September 17, 284. Egyptian Christians, for example, began to calculate the “Diocletian era” as beginning on New Year’s Day of that year: August 29, 284. It was also known by some as the “Era of the Martyrs” and was a widely used dating method until the 8^th century. Abyssinian and Coptic Christians still use it.

In the 6^th century, a Scythian monk, Dionysius Exiguus (Dionysius “the short”), attempted to reconcile a number of different tables that were used for calculating future Easters. He ignored dates that had been calculated based on the era of the “tyrant” Diocletian, but began to number the years from what he considered to be the “Year of our Lord Jesus Christ,” that is, from his incarnation. Unfortunately, Dionysius ignored earlier attempts to date Jesus’s birth (as we saw above, many had concluded that it occurred in years equivalent to our 3/2 BC) and reckoned the birth of Jesus as occurring on December 25, 1 BC or 1 AD (scholars are divided on this point).

Dionysius’s efforts have resulted in the peculiar situation in which Jesus’s birth is now reckoned to have occurred “Before Christ” and, according to Dionysius, after Herod’s death despite New Testament evidence to the contrary. It is clear, however, based on the best evidence that Herod died in 750 AUC (in our reckoning 4 BC) and Jesus was born shortly before that.

Are either the dates January 6 or December 25 historically probable as the dates of Jesus’s birth? The oldest traditions agree that Jesus was conceived in the spring and born in the mid-winter. But we cannot say with certainty when or especially on what date Jesus was born. January 1 and December 25 have just as much chance as any of being historically correct. We can never know for certain, so maybe it is best not to worry about it and just enjoy the season. Merry Christmas.