When was Jesus born?
And, how is it possible that Jesus is born “Before Christ”?

Dionysius Exiguus, a monk from Russia who died about 544, was asked by Pope John I to set out the dates for Easter from the years 527 to 626. It seems that the Pope was keen to produce some order in the celebration of Easter. Dionysius decided to begin with what he considered to be the year of Jesus' birth. He chose, from the evidence known to him, the year in which Rome had been founded and determined that Jesus had been born 753 years later.

He was almost certainly acquainted with a suggestion by Hippolytus (170–236) that the date of Jesus' birth was December 25, but the trouble was that Hippolytus had not backed up this claim with sound arguments. Dionysius, however, had just the argument:

·  His contemporaries claimed that God created the earth on March 25.

·  This is the traditional date of the Vernal (Spring) Equinox and New Year’s Day for many cultures.

·  It was inconceivable that the son of God could have been in any way imperfect.

·  Therefore Jesus must have been conceived on March 25.

·  This meant that he must have been born nine months later—December 25.

(Dionysius also concluded that, as a perfect being, Jesus could not have lived an incomplete life so he must have started his “New life with the Father in Heaven” with his death on March 25 as well!)

December 25 was an auspicious choice. In 274, in Rome, the Emperor Aurelian declared December 25 a civic holiday in celebration of the birth of Mithras, the sun god. By 336, in that same city, Christians countered by celebrating the birth of Jesus, the son of God, on December 25—we can’t beat the celebration down, so we will change the reason for the celebration.

Christians in Antiochin 375 celebrated the birth of Jesus on January 6. Christians in Alexandria did not begin to celebrate Christmas at all until 430. So until Dionysius came along there was confusion over dates, and debates raged, even over the usefulness of celebrating the birth of Jesus at all. What had been universally important for all Christians—the pre-eminent event—was the celebration of Easter.

When, in 527, he formalized the date of Jesus' birth, Dionysius put Christmas on the map. Jesus was born, he declared, on December 25 in the Roman year 753. Dionysius then suspended time for a few days, declaring January 1, 754—New Year's day in Rome—as the first year in a new era of world history.

With a stroke of ingenuity Dionysius had managed to shift the attention of the church from Easter to Christmas. From this point in time it seemed only logical to celebrate the birth of Jesus before his death. If Jesus' death by crucifixion had made possible salvation for all people everywhere, so the argument went, then his birth was the sign that God was identifying with human kind by taking human form.

When was Jesus born?

Dionysius (527 AD) calculates how many years its been since the Birth of Jesus, believed to be the Promised Messiah
The Roman Empire is approximately 753 years old when Jesus is believed to be born
0 AUC / Roman Empire
is about 743 years old / 753
AUC / 0 AD / Jesus’ birth was about 527 years ago according to Dionysius’ Calculation / 527
But, Matthew tells us that Jesus was born during the Kingship of Herod the Great who dies in the year 751 of the Roman Empire; therefore, Jesus had to be born about 4 BC, not in the year 0.
0 AUC / From the founding of Rome until Herod’s Death= 751 years / 751 AUC / 753
AUC / 0 AD / Jesus is actually born 2-4 years before the original calculations say he was. / 537

But Dionysius made a mistake in his calculations. Perhaps he had never read the gospel account of the birth of Jesus. In Matthew Jesus is said to have been born while Herod was still King (2:1). That would translate into 4 B.C. (or even earlier) according to the calculations of Dionysius. As a consequence, for Christians, the year 2000is not two thousand years after the birth of Jesus, but more like 2004.

That was not his only mistake. Dionysius followed the convention of his times and, as the Roman calendar moved from the year 753 to 754, he called the latter "year one" of the New World order—anno domini the year of our Lord. The concept of “naught” or “Zero” didn't come into Europe from Arabia and India until about two hundred years later. As a result, centuries end with naught and begin with the digit one. So for us the year 2000 is the end of one millennium but it is not the beginning of the next: that will occur in 2001.

As if the aforementioned math were not interesting enough, the following will drive you over the edge:

Later, when Pope Gregory tidied up the calendar on 24 February 1582, the calendar lost eleven days. To synchronize the calendar of Dionysius with the movement of the sun (the dates of the Equinoxes, both Vernal and Autumnal, began to miss their placement with the sun and moon cycle), October 4 became October 15, and to avoid having to make further adjustments a leap year was introduced. Pope Gregory must also have known of the mistakes made by Dionysius but all he did was to confirm them, perhaps hoping that no one would notice.

We add a second or so at the beginning of each year to keep the calendar and the sun and moon together.

There is one other problem. Bishop Ussher (1581–1656), following the lead of the Jewish Rabbis, worked out the precise year of creation as 4004 B.C. (He knew about Dionysius’ getting the date of Jesus' birth wrong.) But he also advanced the view that the earth had a total life span of six thousand years. In order to come up with this conclusion he based his calculations on all the generations mentioned in the Bible.

The upshot of his calculations was to make January 1, 2000 (or is it 2001) the date for the end of the world! All this is sobering. Dionysius and, for that matter, Pope Gregory XIII and even Bishop Ussher have left us moderns with a strange legacy.

In reality we do not know when Jesus was born—neither the year, the month, nor the day. The chronology of our western calendar is based on mythology masquerading as theology. We do well to treat it all with the humour it deserves and celebrate the end of the millennium this year and the beginning of the next millennium a year from now, perhaps each time raising a glass to the memory of Dionysius.