The Bible does not tell us the exact day of Jesus’ birth, but it gives us clues.
Clue#1 The first chapter of Luke in the Holy Bible tells us that Jesus was conceived by the Holy Spirit in Mary’s womb six months after his cousin, John the Baptist. (See Luke 1:26-40.)
Clue#2 John the Baptist was conceived shortly after his father, Zechariah, received the message from the angel Gabriel. It is written that Zechariah met with Gabriel while he served in the temple. (See Luke 1:8-25).
Theory Based on the Biblical description of Zechariah’s service in the temple, some scholars believe he served during Yom Kippur (in September or October). This means John the Baptist would have been conceived in September or October.
Conclusion If John the Baptist was conceived in October and Jesus was conceived six months later, Jesus was conceived in Mary’s womb by the Holy Spirit in April. If Mary conceived on April 2, Jesus would have been born on December 25.
I hope this nerdy calculation helps you draw closer to Christ and glorify God this holiday season. May your Christmas be merry and meaningful!