The same day I made that unfortunate discovery, I also made a fortunate one!
As I mentioned previously, we have multiple lines of evidence converging to show that Jesus was born in the year 3/2 B.C.
There are multiple sources from the early Church (around a dozen) that show this to be the case. While there are a tiny number of sources suggesting other years, the overwhelming majority indicate 3/2 B.C. as being the correct time frame for Our Lord's birth.
Most of the sources we have that address the subject are a couple three (four) centuries after the time of Christ and so are open to some question, though the convergence of all of them on this year is quite weighty.
As I was thinking about this, my mind went back to the chronological references in Luke's gospel, and I realized something that caused me to cheer. I'd never done the math before, but as soon as I did, it was obvious!
As is well known, Luke introduces the Annunciation this way in chapter 2 of his gospel:
 In those days a decree went out from Caesar Augustus that all the world should be enrolled.  This was the first enrollment, when Quirinius was governor of Syria.
Now, the enrollment under Quinirius has long been a subject of discussion. If you assume it was a census, as many do, then it's going to cause you problems, because there was no census in the appropriate time frame. There was, however, a broad-based registration or "enrollment," that occurred in this period, but that's a story for another post.
But the big point is that Jesus was born during the reign of Augustus Caesar–a point also confirmed by the fact both Matthew and Luke record him as being born during the reign of Herod the Great, who reigned during the time of Augustus (precisely when Herod died during that reign is also a point of discussion–and a subject for another post).
So when did Augustus reign?
In part, it depends on when you count the beginning of his reign. He was the grand nephew of Julius Caesar, and Julius Caesar was assassinated in 44 B.C. Augustus (who at different points in his career was also known as Octavius and Octavian) became his posthumously-adopted heir and successor. In 43 B.C. the Roman Senate awarded him the title "Imperator," which in English is "Emperor." He thus became the first Roman emperor.
Later, after the Battle of Actium in 31 B.C. and the suicides of Mark Anthony and Cleopatra in 30 B.C., Augustus became sole ruler of the empire.
You can thus date his reign either from around 44/43 B.C. or 30/31 B.C.
However you chose to reckong it, Augustus had a remarkably lengthy reign, which finally came to a close in A.D. 14, when he died.
He was then succeeded by his adopted son, Tiberius, who became the second Roman emperor.
Taking a broad view, Augustus reigned from 43 B.C. to A.D. 14, and both Luke and (by implication) Matthew, place his reign in this period.
Good enough. But can we make the date more specific?
If we turn the page and start reading Luke chapter 3, we find the following statement regarding the ministry of John the Baptist:
 In the fifteenth year of the reign of Tiberius Caesar, Pontius Pilate being governor of Judea, and Herod being tetrarch of Galilee, and his brother Philip tetrarch of the region of Iturae'a and Trachoni'tis, and Lysa'ni-as tetrarch of Abile'ne, in the high-priesthood of Annas and Ca'iaphas, the word of God came to John the son of Zechari'ah in the wilderness;  and he went into all the region about the Jordan, preaching a baptism of repentance for the forgiveness of sins.  As it is written in the book of the words of Isaiah the prophet, "The voice of one crying in the wilderness"
The Herod in t.his passage isn't Herod the Great–he was long dead–but the important part of the quote is the reference to the fifteenth year of Tiberius Caesar, who had succeeded Augustus upon the latter's death.
The way things worked in the ancient world, they often counted the first part of a year of a ruler's reign as that ruler's first year, then changing to the second year when the next civil new year began.
To give a somewhat bent example based on our own practice of having the civil new year begin on January 1st (a practice that was not universal in the ancient world), if Ruler X began his reign on September 1st in year Y then the period from September 1st to December 31st would be reckoned as his first year. His "second year" would then begin on January 1st.
Given that parts of years could count as a ruler's first year, the fifteenth year of Tiberius could be either in what we would reckon as his fourteenth or fifteenth year.
So when was that?
Augustus died in A.D. 14, so in Luke 3:1, the Evangelist is giving us a pretty specific reference to A.D. 28-29 (A.D. 14 + 14/15 years of Tiberius's rule = A.D. 28/29).
Fine. What does this have to do with the birth of Jesus?
Luke describes the (apparent) beginning of John the Baptist's ministry in A.D. 28/29, and right here in chapter 3 of the gospel he refers to Jesus' baptism and the beginning of Jesus' ministry. He doesn't say that these occurred in the same year, but he certainly gives that impression–or at least the impression that there wasn't a significant lapse of time between them.
So this: Luke also records in chapter 3 that, after the baptism and before the testing in the wilderness, that:
 Jesus, when he began his ministry, was about thirty years of age . . .
Thus, if we assume that Jesus began his ministry shortly after John the Baptist, as Luke seems to imply, and if John the Baptist began his ministry in A.D. 28/29, and if Jesus was approximately 30 years old at this point, then all we need to do is subtract 30 from the current year to find out the approximate year of Jesus' birth.
Using a modern number line that includes the number 0, one would thus think that Jesus' birth occurred in -2/-1.
But they didn't have the number 0 in the Roman world, and there is no "Year 0" on the B.C./A.D. timeline. The A.D. (Latin, Anno Domini = "Year of the Lord") years are the years counting from Jesus birth (the first year of his birth, the second year, etc.). The B.C. ("Before Christ") years are the years before his birth (the first year before, the second year, etc.). On neither reckoning is there a "Year 0."
As a result, we need to subtract an additional year to any B.C. dates to account for the lack of a 0 year.
This means that if Christ was born in what you'd think would be -2/-1 then it would really be 3/2 B.C.–the exact same year that we have multiple independent sources from early Church history pointing to.
Only here we have St. Luke himself–an undisputed first century author (who was, based on internal evidence in the gospel and Acts, almost certainly writing from Rome around the year A.D. 62).
That's important and early testimony about when Our Lord was born!
What do you think?