According to Luke 1:24-26, Mary conceived Jesus in the sixth month of Elizabeth’s pregnancy with John the Baptist. This means that Jesus was born 15 months after the angel Gabriel appeared to Elizabeth’s husband, Zacharias, and informed him that his wife would bear a child.
According to Luke 1:5, Zacharias was a priest of the division of Abijah. Luke 1:8 says that Gabriel appeared to Zacharias while he was serving as a priest in the Temple.
We know from the Talmud and other sources that the division of Abijah served as priests during the second half of the fourth month of the Jewish religious calendar — which would have put it in late June (the Jewish religious calendar begins in March with Passover).
Fifteen months later would place the birth of Jesus in the seventh month of the Jewish calendar. That would be in the fall of the year, in either late September or early October. His conception, not His birth, would have occurred in December of the previous year.
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