Question: When was our Lord born?
Answer: Modern man has a preoccupation with exact dates, times, and locations that simply did not and could not have occupied the minds of people in the ancient world -- or even a few hundred years ago. Today an inexpensive Global Positioning System receiver will give you the time to fractions of a second, and tell you where you are on the earth within a few yards, and often can tell you your height above sea level. We take it for granted that everyone knows, and can prove, when and where they were born. By the time they die, their marriages and their children will have been recorded; and the time, location, and cause of their deaths will be recorded shortly thereafter.
In the ancient world, this sort of record keeping was unheard of. Approximate dates were recorded by reference to events that were known to all. The Prophet Amos, for example, dates his writing "two years before the earthquake" that shook Jerusalem.1 In dating the birth of our Lord, Saint Luke mentions the census ordered by Rome; that Augustus reigned as Caesar, and that Cyrinus was governor of Syria.2
Among the ancients, there were calendars, to be sure -- but for the most part these were used to predict religious events -- later on they might be used for commercial transactions -- but not to record information about average individuals. Some societies used lunar calendars, marking a month every 29½ days, making the year a little over 354 days long. Others used solar calendars, usually of 365 days, but with a diverse number of systems for dividing the year into months. Some systems inserted extra days to make the solar and lunar computations agree, while others inserted extra months -- some simply didn't bother.
Various cultures had various dates for the beginnings of their calendar keeping. Some, like the Jews, claimed to place the first day or year of their record keeping at creation (3761 B.C.). The Greeks measured in terms of the first Olympic games (776 B.C.) The Romans dated from "the founding of the City" (AUC) of Rome (753 B.C.)
The idea of basing our calendar on the birth of Christ came in 532 A.D. at the suggestion of the historian Dionysius Exiguus. Actually, it was based on the date of the Incarnation, so he had his calendar start on March 25th, A.D. 1, and assigned the birth of Christ to December 25th of the same year. But today it is fairly certain that Dionysius underestimated the number of years between the Nativity and his own time, thus creating the anomaly of Christ being born as much as 6 B.C.
The date, December 25th (January 7th in the Julian calendar), is almost universally accepted as the ceremonial date, but this unanimity took several centuries to achieve. Perhaps the best explanation of its origin is in the desire of the Popes to replace the pagan feast of "Sol invictus" with a Christian observance. Just slightly after the winter solstice this date is perhaps the earliest possible time for observing the lengthening of the winter day. The Catholic Encyclopedia, s.v. "Christmas" treats the matter in detail. On the Internet, visit http://www.newadvent.org/cathen/03724b.htm.
The following article, also taken from the Catholic Encyclopedia illustrates the difficulty of pinpointing a date from the Gospels and other records of our Lord's time:
When was Jesus Christ born? Why, on Christmas, of course. And it matters much less that we know the precise date of that blessed day than that we observe it with gratefulness that our Lord became one of us for our salvation.
NOTES:Amos i: 1.