Contrary to popular belief, the Bible doesn't actually mention a specific date for Jesus' birth. In fact, most historians believe he was probably born in the spring, hence the Bible's description of shepherds herding animals. But in the 4th century, when the Catholic Church decided to recognize Jesus' birth as an official holiday, Pope Julius I chose December 25 for the Feast of the Nativity. That the date happened to coincide with the pagan festival known as Saturnalia must have been pure coincidence.
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