Q. Yo! You never did answer my question on why we have 12 days of Christmas...
A. Apologies!
Well, to answer that, now would be a good time to answer your question on why we celebrate Christmas on 25th December.
Q. Finally!
A. So. Before the Church decided to fix the celebration of Christmas on 25th December, there were already two older feasts celebrated on that day, one pagan the other Jewish.
The pagan one celebrated the victory of "Unconquered Sun" over darkness of the Winter Solstice. Around 22nd Dec in the northern hemisphere, nights are longest and days shortest. By the 24th, it was clear days were becoming longer and nights shorter. From 17th - 24th, the Romans celebrated the festival of light (Saturnalia) that climaxed on 25th December.
For the Jews, 25th Dec was anniversary rededication of the Temple of Jerusalem back in 165BC after it had been abominably desecrated by the Greek king Antiochus IV Epiphanes. The Jews celebrated this as the feast of the Dedication, Feast of Lights or Hanukkah.
As one author writes, "These two feasts brought together a twofold symbolism. They were the perfect match for Christians to celebrate Christ’s birth.
On the one hand, the pagan feast of Saturnalia, honoring the birth of the Unconquered Sun, was a wonderful sign of the Messiah as the new sun and son of salvation, a ray of hope for humanity. On the other hand, the Jewish feast of the Hanukkah meant that God had re-entered the temple, and creation, after being thrown out by the sins of humanity."
8thJanuary 2016