Several pagen holidays around that time of year. We still speak of the Yuletide season, a Nordic celebration, but lot has been said about observation of Mithra, who is said to have many traditions similar to Christ's.
Constantine, in a plan to get his people to embrace his new religion, adopted Christ's birth as being a replacement for the page feasts. Likewise, Easter was taken from pagen roots. Many of the symbols of the holidays have been carried forth to the US.