On this Twelfth Day of Christmas my true Love gave to me three swans a-swimming!! Well, who hasn't got that song mixed up! Nevertheless, a lovely gift.
Starting in the 4th century, the birth of Jesus was celebrated on the winter solstice. In calendars in use in the West the solstice was December 25. In calendars in use in the East the solstice was January 6. Eventually the 12 days between these two dates were set aside to celebrate the birth of God-Become-Flesh. Such an earth changing event deserves a long celebration and a special song.