CrossTalk: Calculating Christ's Birthday

I am writing this devotion on the 12th and last day of Christmas. These 12 days of Christmas mark the time between Christmas Day, December 25, and the Festival of the Epiphany on January 6. But how did these two dates become important in connection to Christmas?

Even though Christmas wasn’t really celebrated until the middle of the fourth century, people were still interested in knowing the date of Jesus’ birth. In fact, around the year 200 AD, two different parts of the Church calculated two different dates 12 days apart. Tertullian, a Latin Christian in northern Africa, came up with December 25, while an unknown Greek Christian in the near-East thought it was January 6.

Rather than resolving these two dates, it simply became the custom that eastern, Greek-speaking Christians observed January 6, while western, Latin-speaking Christians celebrated Christmas on December 25. We in the west also developed the custom of celebrating the Greek Christmas (January 6) as the “Christmas for the gentiles,” the day when the first non-Jews saw the baby Jesus.

Besides these two dates, there have been both ancient and modern scholars who calculated still other dates for Jesus’ birth. The Bible itself does not record the date. Neither am I aware of any tradition handed down from Mary or Jesus’ brothers. So we really shouldn’t argue too vigorously about it.

Still, it is worth understanding why the days between December 25 and January 6 have been observed by all Christians for 1,800 years. The popular internet rumor that we simply borrowed December 25 from the pagan Romans doesn’t hold water. Besides, it cannot account for the January date at all.

In fact, the earliest datings of Jesus’ birth aren’t concerned with Jesus’ birth so much as they are concerned with Jesus’ conception! Tertullian and others set out to calculate the day of Jesus’ conception. Once they reckoned that, they simply assumed that the birthday would be nine months later.

Around the year 200 AD, Tertullian concluded that Jesus was conceived by the Holy Ghost on March 25. That would make His birthday on December 25. In the same way, the Greek scholar in the east came up with April 6th as the day of Jesus’ conception, and so January 6 would be the natural time for his birth.

But what in the world would make these people think that could know the date of Jesus’ conception? Truth be told, it was a purely theological idea. Both men were operating under the widely-shared notion that great men, which Jesus surely was, always died on the very same day that they were conceived.

Tertullian and his counterpart in the east both set out to calculate the day of Jesus’ crucifixion. They each came to different dates, but everything else flowed from that. Our December 25 date assumes that Jesus was crucified on March 25. The Greek Orthodox date of January 6 assumes that Jesus was crucified on April 6.

Regardless of whether you are an eastern Christian or a western Christian, Christmas has always been connected to Good Friday.

What a beautiful thought! Jesus was born to be our Savior from sin, death and hell. He was born to give His body for the life of the world. He was born to be King of the Jews. All of this happened on the cross. There He “destroyed the works of the devil” (John 3:8). On that day He said, “This is My Body given for you” (Luke 22:-19). There He wore the crown and hung under the title, “Jesus of Nazareth, King of the Jews” (John 19:19).

Maybe this is what the hymnist William Dix was thinking when he wrote “What Child Is This?” In the second verse of this Christmas classic we sing, “Nails, spear shall pierce Him though, The cross be borne for me, for you. Hail, hail the Word made flesh, the Babe, the Son of Mary.”