The father of John the Baptiser, is the key to knowing when Mary became pregnant. The time when he was charged with Temple service, can be figured out, Mary came soon to tell her cousin the news that was foretold her about the Messiah. John was already within the womb, and Yeshua was within Mary. Figure out 9 months, and voila’....closer to September for his birth.
John, as a kind of Elijah, was likely born on 14, Nisan (Eliyahu does show up for Passover). Sukkot begins 180 days (6 months) later. If John was born on Passover, his cousin Yeshua (”Jesus”) was born during Sukkot - which is almost always late September or early October on the Gregorian calendar.
Yes; that is the key. The Course of Abia, the time of his Temple Service, gives June for Zacharias' encounter in the Temple with Gabriel, telling him his wife, Elizabeth, would conceive.
Then we have John 6 months in the womb in December, giving the date of Jesus' conception.
December 25 becomes the date Jesus began to dwell upon the earth...in Mary's womb.
His birth would them be on or about the Feast of Tabernacles.
So Yeshua would likely be born right around the festival of Sukkot...