Why is Christmas on December 25?

Congratulations–you survived the longest night of the year. (Unless you live in the Southern Hemisphere; more on that in a moment.)

The planet you inhabit tilts on its axis at a 23.44-degree angle. When the Northern Hemisphere tilts toward the sun, we get summer. When it tilts away, we get winter. When earth tilts as far from the sun as possible, which happened yesterday, the sun sets earlier than it does all year and we have the annual Winter Solstice. The Southern Hemisphere experiences precisely the opposite phenomena.

Our meteorological experience relates directly to Christmas, but in an indirect way.

When was Jesus born?

It is unlikely that Jesus was born on December 25. Shepherds were “out in the field, keeping watch over the flocks by night” when the angels announced the Messiah’s birth to them (Luke 2:8). In the cold month of December, their sheep would have been corralled around a fire. Luke’s reference points to the spring lambing season as the more likely time of Jesus’ birth.

Why, then, do we celebrate Christmas on December 25?

One explanation relates to pagan celebrations. The Romans held their mid-winter Saturnalia festival in late December, a Mardi Gras-like party marked by immorality. In AD 274, the Roman emperor Aurelian established the feast of the birth of Sol Invictus (the Unconquered Sun) on December 25, coinciding with the winter solstice. In response, Christians located the birth of God’s Son on that day as a way of inviting pagans to his worship.

However, many scholars dispute this explanation. A second theory is related to Jesus’ death at Passover, which some early Christians dated as March 25. They theorized that Jesus was conceived and crucified on the same day. Therefore, he would have been born nine months after March 25, on December 25.

While no one is certain of the date Jesus was born, it seems entirely appropriate that we celebrate the birth of God’s Son near the time when we most need the sun. Our…