Though widely celebrated on Dec. 25, the actual birth date of Jesus Christ remains unknown, as of 2015. Many researchers estimate that Jesus was born in the early fall of 2 B.C.
According to biblical records, shepherds were outside watching their flocks at the time of Jesus' birth, and Jesus' parents traveled to Bethlehem to register in a census. Neither of these would have occurred in December, a cold, rainy month in Judea. Researchers believe the celebration of Christmas originated as a substitution for non-Christian celebrations of the winter solstice. Some theorize that Christians chose Dec. 25 to encourage the spread of Christianity throughout the Roman world.