December 25th was chosen for Christmas to coincide with a pre-existent Pagan Roman holiday, Saturnalia. December 25th was also recognized in ancient times as the birth day of various other god-men such as Attis and Mithra. All were linked to the winter solstice, which occurs about December 21.
(via pagangirl)
Wasn’t Saturnalia a week long festival though? Maybe even a month long. Hang on… Wikipedia has the official celebration...