"...for the first three centuries of Christianity’s existence, Jesus Christ’s birth wasn’t celebrated at all. The religion’s most significant holidays were Epiphany on January 6, which commemorated the arrival of the Magi after Jesus’ birth, and Easter, which celebrated Jesus’ resurrection. The first official mention of December 25 as a holiday honoring Jesus’ birthday appears in an early Roman calendar from 336 A.D." (source)
And here's an interesting video for those of you who are interested in learning more about the Christmas holiday.
I'm a real trivia junkie, so I'm always tuned into this kind of stuff. How about you?