I have a long commute. In the summertime it is beautiful. In the winter, leaving the silent house in the darkness before the snowplow trucks are awake, I and my trusty 4wd Tacoma set out in the blowing blizzard for the money hour (each way) trek. I have, therefore, over the past 5 years, become a great fan of The Great Courses and their many college-level courses on CD, and have even recommended one of their courses on Latin, here. Recently I listened to a course on Medieval Europe, overall very good, but in the section on early Christianity in the former Roman provinces now know as Western Europe it was obligatory for our professor, as I suppose it must be for all contemporary professors who wish to keep their academic appointments, to roll out the tired old tripe about Christmas Day and Saturnalia. It goes something like this (I am paraphrasing, not quoting directly):
"Early Christianity recycled pagan holidays just as it recycled pagan temples. The reason that the date of 25 December was picked for the birth of Christ was because it was close to the pagan holiday of Saturnalia, a period of hard partying in the old Roman Empire which occurred around the time of the winter solstice (21 December). Scholars agree that the date of Jesus' birth is unknown, and the Gospels are 'conflicted' (really?) but most put it in the spring or summer."
Variants on this theme note that there were many pre-Christian celebrations on or around the winter solstice, and modern day pagans have created an entire industry around the old Druid "Yule" celebration of welcoming back the sun. This includes, of course, various rituals for contemporary pagan goddesses - no mention if there are any similar rituals for modern day pagan gods. Anyway, the summary point is that the modern notion of Xmas is just a pastiche of various resurrected (or invented) pagan rituals along with a heavy dosing of myth, sentiment, excessive shopping and Hollywood grinchisms, some of which have been neatly summarized here. Into this slurry is injected, and presented as fact, this "no one really knows when Christ was born." I have, in fact, heard this "fact" presented as fact from more than one Catholic pulpit.
There is an analogy. When I was beginning to study the Church prior to becoming Catholic, a meme I not infrequently came across was that the Gospels weren't really written by Matthew, Mark, Luke or John. They were written by someone else. Or several someone elses.
"Most scholars doubt [the Gospel's] authorship by Matthew... a growing consensus says the author was a converted rabbi or someone highly educated in rabbinical lore." (Christ Among Us, 6th Ed., A. Wilhelm, HarperCollins Publishers, 1996, pg. 190)
[The Gospel of John] "was probably written just before 100 C.E.... by an unknown author..." (ibid, pg 191) (Note that an ostensibly Catholic catechism used the politically correct "C.E" - "Common Era" - rather than the A.D. Anna Domini, or "after death".)
This sort of stuff bothered me from the very first. Granted, the Gospel writers do not name themselves in their books, but it is, and has been since the earliest days of the Church, the understanding that the Gospels were written by the four men named as authors. If the names of the authors were simply made up, or simply "assigned" to these men, which is after all, what these priests and theologians are claiming, well, that would mean that the Church is not very faithful in little things such as the identity of the Gospel writers. And, if the Church is unfaithful in this little thing, what other little things has she been unfaithful in? How about big things? Is she faithful in the big things like these: death and judgement, heaven and hell? Or, does she bend the truth in the big things as well from time to time? Without getting into the topic of dogma, definitive teachings and Tradition with a capital "T" versus tradition with aa lowercase "t" - that is well beyond the limits of this little post - suffice it to say that I choose to believe that the Gospels were in fact written (perhaps with research help, scribes, etc, but nevertheless authored) by four real men whose names were Matthew, Mark, Luke and John. If you want to view that view as an abdication of intellect to the simplistic "God said it, I believe it, and that settles it" assertion found on the occasional bumper sticker, that's OK with me.
So. The Church teaches that the Feast of the Nativity, the day Christ was born, is Christmas Day, 25 December, an handful of days after the winter solstice, the shortest day of the year. Further, a significant symbolic aspect of the date of HIs birth is that the days are beginning to lengthen, just as the Christ Child brought light into the world. There it is. All of the confabulation surrounding the actual date of Jesus' birth notwithstanding, I see no reason why He couldn't have been born on December 25th. Why not? If God is truly who we think He is, He could certainly arrange for that event to take place on the day of the Church -- His Church, so we are to believe-- says it happened.
So. I will continue in my quaint belief that Jesus was, truly and in fact, born on Christmas Day, exactly as advertised. I believe, an hope, that the Church is telling the truth in this little thing. And I wish you and yours a very merry and blessed Christmas indeed.