Since the gospels do not offer many clues that would point to late December as the time of Jesus birth, many have asked how December 25th was chosen to celebrate the birth of Christ?
Critics of Christmas often point to pagan celebrations centered on the winter solstice as the source of December 25th as a Christian holiday, but there are no writings from secular or early Christian sources that would suggest this origin, it is merely speculation from those with little regard for the history of Christmas. This myth is so prevalent, some Christians even avoid the Christmas celebration for fear of participating in pagan rituals, but this need not be so.
The true source of the December 25 date grew from Jewish Rabbinical tradition as recorded in the Talmud as early as the 2nd century A.D. Malachi 4 predicts that Messiah's appearance would be announced by Elijah the prophet. So the annual Seder feast marking the Passover includes opening the door to check for the appearance of God's prophet to proclaim the coming of the Messiah.
Since the crucifixion of Jesus was at the time of Passover, some early church fathers thought it plausible that the Annunciation of Jesus coming by God's messenger Gabriel could serve the same purpose. So they calculated date of the Passover the year that Jesus died and came up with March 25 for the date his death. So they reasoned that the annunciation of Gabriel and the conception of Mary would be on the same date, during the time of Passover. To this day the Roman church celebrates a feast of the Annunciation on March 25. Counting forward 9 months from March 25th, they arrived at December 25th as a date to celebrate the birth of Messiah. Understand that the early church following Jewish tradition was fond of feasts and special times of worship and used those rituals to teach the theology of the church before the age of widespread literacy and ownership of bibles. So around the 3rd and 4th century you find the first celebrations of Christmas recorded as a special mass that taught the nativity of Christ.
Now although this idea of a Passover annunciation is speculative it has a certain logic and symmetry that is appealing to some people, but they are not hard conclusions that you can reach based upon scripture, and should never be expressed with certainty. But what if the Talmud is right and the annunciation really was connected to the Prophecy of Malachi and did occur at Passover? Well in a way I think there is some truth to that idea.
4 "Remember the Law of Moses, My servant, Which I commanded him in Horeb for all Israel, With the statutes and judgments. 5 Behold, I will send you Elijah the prophet before the coming of the great and dreadful day of the LORD. 6 And he will turn the hearts of the fathers to the children, and the hearts of the children to their fathers, Lest I come and strike the earth with a curse."
Now for us who know the New Testament we would connect that passage to Revelation where many believe one of the two witnesses of the Apocalypse will be a resurrected Elijah announcing the 2nd coming of Jesus and judgment day, but is there also a connection to the first coming, the incarnation of the Christ?
Malachi 4:6 should sound familiar because a part of it was quoted by the Angel Gabriel, not when he spoke to Mary but rather when he spoke to Zacharias regarding John in Luke 1: 16 And he will turn many of the children of Israel to the Lord their God. 17 He will also go before Him in the spirit and power of Elijah, 'to turn the hearts of the fathers to the children,' and the disobedient to the wisdom of the just, to make ready a people prepared for the Lord.
The Angel was announcing the one who would have the spirit and power of Elijah the prophet, to prepare the way for the Lord, and this prophet was John the Baptist. But in announcing John, the angel was also announcing the coming of the Lord, and this announcement very well could have been in the Hebrew Month of Nisan during Passover and that would likely be late March, meaning that the child born 9 months after the Passover annunciation was John not Jesus, and Jesus was born 6 months later in the summer time around May or June. Summer is a time where shepherds would have been living out in the fields grazing sheep in the pastures around Bethlehem. So Malachi 4:4 ties the annunciation of Messiah to Passover (remembering the Exodus) and Malachi 4:6 ties it to the conception of John the Baptist and the spirit of Elijah the prophet.