First off, they didn't exactly keep birth records of the common folk in 0 or 1 or 2 AD (not to say that Jesus was common, but well, you know the story.) Secondly, even if they did, there's the problem of leap year. Every four years the powers that be add an extra day to compensate for a less than perfect rotation of the earth. The Romans even didn't know about that, convoluting time and calendars even more.
Plus some people back then used a lunar calendar and some used the solar version that we use today. Finally, the authors of the Gospels (Mathew and Luke particularly) either didn't know or didn't think it was important enough to mention the date of Jesus' birth. Who even knows if they recognized birthdays in ancient Judea?
The bottom line is that nobody knows the exact date of Jesus' birth, but the smart money is betting that it was sometime in early spring. There's some historical data, but the best hint is that famous story about shepherds tending their flocks by night. Shepherds tend to only stay up with the sheep during lambing season, and lambing season is in spring. But since no one knows, you might as well go along with the spirit of the season and enjoy all the cheer and good will towards men.
There is, however, some interesting history to the day we choose to remember the birth of the Christ child. It's not just some random date that somebody pulled out of a hat you know.
There have been festivals of every sort around the winter solstice going back to the Babylonians. But it was the Roman Emperor
Aurelia who fixed the actual date. He called December 25th "The Birthday of the Unconquered Sun", and put it right in the middle of the feast of Saturnalia. (The Romans really knew how to have a feast: Saturnalia lasted a week.)
This was a always a time a great merry making there were big dinners, halls bedecked with laurels and green trees, people carrying lighted candles through the streets, and the giving of gifts was a common practice. In fact, you might say that the Christmas spirit is really the spirit of Saturnalia passed on over time.
The Christians, in the meantime, were having the "Mass of Christ" at various times and places. This wasn't a commemoration of the birth of Jesus so much as it was a time to reflect on His life and acts. So, when Constantine made Christianity the religion of Rome, the Catholics needed a way to convert the pagans running around the streets of Rome with their candles and presents to Christian practices.
One imagines it went a little something like this: "You have an unconquered sun, we have an unconquered Son. You give gifts -- we have wise men bringing gifts. You have bonfires and lamps and candles -- we have a new star. It's not really all that hard put the two together." Or something like that.
So, the pagans became Christians, and everybody got a day to celebrate selflessness, joy, and light.
***In association with www.MyMerrychristmas.com**