Misplaced Obsessions: Understanding Why Christmas Is On December 25th.

  • Article (blog post)
  • 1500 words
  • Level: all audiences

Fr. James Kurzynski writes on the subject of the date of Jesus’s birth in this post on The Catholic Astronomer blog.  Know “the date” is complicated, as Fr. Kurzynski explains:

So, can we find December 25th referenced as the date of Jesus’ birth in the writings of the early Church Fathers? Yes, we can… with some presumptions that are VERY important to take into account. A basic Google search on when we find the first reference to December 25th as the date of Jesus’ birth will bring you to Hyppolytus of Rome (170AD – 235AD). Most online citations will boldly affirm that Hyppolytus wrote that Jesus was born on December 25th. The problem is, that’s not what Hyppolytus said. He actually said that Jesus was born on the 25th day of the ninth month. What Hyppolytus is referencing is the Jewish month of Kislev. Of particular interest, the 25th of Kislev in Jewish culture is the celebration of Hanukkah or the “Feast of Lights.” Might there be a connection being made between this Jewish feast and Jesus as the “light of the world?”

To get from the 25th of Kislev to December 25th, we first make a pit stop at the Julian Calendar, which was determined to be slipping each year through the work of the first Vatican Observatory in the Tower of the Winds, leading to the reformed Gregorian Calendar. The Christian West embraced the Gregorian reforms while the Christian East chose to remain on the Julian Calendar. This is why, to this day, there are two dates in the Christian world for the celebration of Jesus’ birth: December 25th in the Christian West and January 7th in the Christian East. Further, we see that the Jewish calendar is a lunar calendar so the 25th of Kislev, Hanukkah, seldom coincides with December 25th. In short, the presumption of when Jesus was born is far more difficult to pin down than one would think.

Click here to read the full article on The Catholic Astronomer – the blog of the Vatican Observatory Foundation.

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