Humans have latched onto dating systems and chronologies as the means by which we keep track of ourselves vis a vis others in time. We keep track of where we are in terms of our own passing, our own age, and the passing of our own time, our generation, and the passing of centuries, even millennia. There have been and are many different kinds of dating systems. The one universal dating system upon which governments, business, travel, and education are based is to measure years chronologically according to centuries and millennia. We date according to Common Era (CE) and Before Common Era (BCE) to provide reference of human passing over time. But what do these mean, CE and BCE? Upon what are they based? Where do they derive? The birth of the child Jesus—the incarnation. Time as we measure it today is linked to a religious, even a supernatural, moment.

The birth of God become man, the nativity of the Son of God, the act of the Word becoming flesh, the incarnation of Christ, the Messiah, is the central moment in human history if for no other reason than that the birth of Jesus in Bethlehem two thousand years ago has made such a profound impact on human expression, thought, and institutions. This statement should go without saying, but if it does not, then consider the following most obvious example of the continuing impact of the Incarnation. The year of this writing, 2023, is a numerical symbol for a solar year, the 2023^th since some important event, so important an event that clocks, calendars, cell phones, governments, security agencies, world financial institutions, and more, base their systems, their very institutional beings, on an event that happened so long ago. How did this dating system emerge, and around what event? The answer to the former question is long and complex, covering centuries of attempts to erect chronological systems around the event, which was like so many other such events that occur everyday and have occurred everyday for the past thousands of years: the birth of a child.

One might assume that an event so important to world history would have been and is well known and celebrated around the world on its anniversary—and it is. One might assume that such a significant event would likewise be so well known in all of its details that the exact time, place, setting, time, and chronology compared to other events would be well known—but not so. Strangely, arriving at a correct date for the birth of Jesus of Nazareth has long been a perplexing, unsolvable problem. Jesus could have been born during any one of a range of a dozen years two millennia ago. Of these, the least probable year for his birth is the year 1. There exist only two sources, the Gospel of Matthew and the Gospel of Luke, which provide any information whatsoever about this central event in the history of humankind. Yet the two Gospels cannot be reconciled chronologically. Indeed, the four sources that purport to provide biographical portraits of Jesus–Matthew, Mark, Luke, and John–as a whole provide limited contradictory accounts of his birth. And yet the birth of Jesus of Nazareth is considered the central event in human history by the religion, Christianity, with the most adherents worldwide, and it has for centuries been the basis for the world’s most commonly accepted dating system: the linear system of Ante Christos (BC) and Anno Domini (AD), since euphemistically renamed to Before the Common Era (BCE) and Common Era (CE).

Time is so important to humans individually, collectively, personally, and institutionally. Yet what is known of time? What is it? Theologians, philosophers, and historians for centuries have tried to uncover the true nature, to comprehend, time. Is time an artificial measure, a tool by which humans trace their own existence? Or, does time have an independent existence, a phenomenon separate from human experience? Is time geologic, the earth carving a temporal path from its beginning to its end? Is time dependent upon human awareness?—hence without humans to know and trace it time is meaningless, nonexistent. Is time an absolute, a constant that can be measured with mechanical devices, a certainty that, as Newton believed, has very little fluctuation, hence allows humans the confidence to base our lives upon it? Clocks, chronometers, and calendars help us to safely trace the passing of years, days, months, which gives us meaning, helps us to know ourselves and our world. Or is time relative, as Einstein believed? Einstein argued in the theory of relativity that time depends on movement, that a person who travels at an extremely high rate of speed experiences time different than a person at rest. Since it depends upon the experience of an individual, time is inconstant and fluctuating, governed by outside forces, significant only insofar as it yields for each person a way to gauge personal movement. According to the theory of relativity, one person’s time is not the same as another person’s time. Although time appears to move quickly in the twenty-first century because humans move rapidly, coming and going, and information is quickly exchanged, seemingly in an instant, does this mean an individual perceives time any differently than someone from the past, say in first-century Rome? Does a person’s bodily movement, the movement of the mind, the aging process, change with changing technology, with rapidity of motion? Is it important to know one’s age or date of birth, to know the year, the month, the day, the hour, the minute, the second? What does it mean to regulate institutions, government, the most minute human events, according to the passage of seconds, minutes, and hours? Does an individual experience life differently by knowing the precise time according to satellites, cellular devices, computers, and atomic clocks?

The Gospel of Matthew records the birth of Jesus as occurring toward the end of the reign of Herod the Great, King of Judaea, who died in the year 4 Ante Christos/Before the Common Era. Matthew’s Gospel portrays the world as in need of a savior; then a star appeared, followed by visitors, the magi, coming from the East. Through the magi, according to Matthew, Herod learned of the birth of the Messiah in Bethlehem, which led the desperate king to order the murder of all children in Bethlehem under the age of two years, according to the period during which the child was purportedly born. Matthew’s account has little precision in terms of actual events, placing several isolated episodes together into one not entirely convincing narrative. Matthew wrote in Greek, the language of learning in the Roman Empire, of which Judaea was a part.

The dating systems used at this time in the Roman Empire were Roman and Greek. According to the former, Roman system, Jesus of Nazareth was born about 749-751, a.u.c. (ab urbe condita, from the legendary founding of Rome by Romulus and Remus). According to the Greek dating system, Jesus of Nazareth was born at the end of the 193^rd Olympiad or beginning of the 194^th Olympiad (an Olympiad having occurred every four years since its founding almost 770 years before)–in short, 6-4, Ante Christos/Before the Common Era.

Luke, who professed at the beginning of his gospel to give his readers an accurate and complete story of the life of Jesus, provided two different accounts of Jesus’s birth that would result in two contradictory dates. Like Matthew, Luke, in chapter one, used episodic accounts, bringing into his narrative the stories of the visits of the angel Gabriel to Zechariah, father of John the Baptist, and Mary mother of Jesus. According to these stories, Jesus was born six months after the birth of John the Baptist, which occurred near the end of the reign of King Herod, which conforms with Matthew’s dating system. Unlike Matthew, however, Luke’s account, in chapters two and three, also provides chronological facts by which to date the birth of Jesus. Luke’s gospel implies simultaneity to several events: the creation of the province of Judaea by the Romans after almost a half century of rule by Herod and Herod Archelaus; Augustus Caesar’s ordering of a census; the subsequent rebellion of Judas of Galilee; and the appointment of Quirinius as Governor of Syria. Luke’s system of dating according to simultaneous public events is as sophisticated as the best Roman historians of the first century. According to Luke, Jesus was born in 760 a.u.c. or two years after the 196^th Olympiad (i.e., 6 Anno Domini/Common Era).

In Luke, chapter three, the historian dated the beginning of Jesus’s ministry to several simultaneous public events: the 15^th year of the reign of Tiberius Caesar, when Pontius Pilate was Procurator of Judaea; Herod Antipas was Tetrarch of Galilee; Philip, son of Herod, was Tetrarch of Ituraea and Trachonitis; Lysanias was Tetrarch of Abilene; and high priests of the Sanhedrin were Annas and his son Caiaphas. Luke also stated in chapter 3, verse 23, that Jesus was about thirty years old when he began his ministry. Had Luke been exact regarding Jesus’s age at this time, then it would be clear that he was born a few years after the death of King Herod, about 1 or 2 Ante Christos/Before the Common Era. Luke’s vague statement in 3:23 does not, however, accord with Matthew, or even with Luke’s earlier statements regarding the incarnation.

Subsequent chronologers who tried to date the birth of Jesus of necessity relied on Matthew and Luke supplemented by the Jewish historian Flavius Josephus. In his Antiquities and History of the Jewish War, Josephus provided confirmation of some of the events and rulers listed in Luke, chapter two. Josephus’ difficulties in dating events is illustrated by his chronology of the Roman destruction of the temple. Rather than relying on the Roman system of ab urbe conditia or the Greek system of Olympiads, Joseph used a Hebrew system according to significant events and the rule of kings.

The problem facing chronologers was, besides the inherent contradictions in the gospels of Matthew and Luke and the lack of an account of Jesus’s birth in the other two gospel writers Mark and John, that ancient historians and scientists disagreed upon which chronological system to use to date events. The great Athenian historian, Thucydides, relied on the reigns of Spartan ephors and Athenian archons to provide dates in his account of the Peloponnesian War. The Greek historian Polybius in his Histories used the more accurate and, from the standpoint of the Greeks, universal dating system of the Olympiads. The Roman historians Livy, writing during the reign of Augustus, and Tacitus, writing about a hundred years later during the reign of Domitian, used, besides the Olympiads, the system of dating events from the founding of the city of Rome (ab urbe conditia). In subsequent centuries, however, Christian writers, unwilling to rely on pagan dating systems, wished for a chronological system based on religious events. Eusebius of Caesarea, writing during the reign of Constantine, added to the pagan dating systems and the chronology of Josephus a hypothetical chronological scheme beginning with the birth of the Patriarch Abraham. Yet three hundred years after the incarnation, Eusebius still struggled to date the birth of Christ.

During Eusebius’ time the Church and Empire, after the conversion of Constantine, were also particularly concerned with dating the Resurrection, that is, Easter. Theologians and chronologers used Greek, Roman, and Hebrew dating systems, until Dionysius Exiguus, in the sixth century, tried to base the reckoning of the dates of Easter not according to the older systems, rather according to a new system based on the greatest event in human history, the incarnation of Christ. He used Luke 3,1 (John the Baptist appeared during the 15^th year of the reign of Tiberius, 28-29 AD) combined with Luke 3:23 (Jesus was about 30 years old when he began his ministry), to estimate the year 1 (the first year or the year of our Lord, Anno Domini).

There is also the system of time developed by Aurelius Augustine, which is a method of understanding the temporal significance of the birth of Jesus of Nazareth that eschews reliance upon dating systems both ancient and modern. Augustine realized that the incarnation and resurrection cannot really be understood according to reason and logic, the stuff upon which chronologies and dating systems are based. Augustine developed another way (other than narrative, chronological history) to understand the incarnation and its significance that eschews precise dating.

In Confessions, Augustine provided a model of personal time thatprovides each person with a model of the individual experience of the life and significance of Christ that has little to do with formal chronologies and history, and public events. It depends upon the old Greek idea of the Logos as developed by Philo Judaeus of Alexandria and the Apostle John. Philo wrote of the Logos: God creates “at once, not merely by uttering a command, but by even thinking of it.” And John wrote, “In the beginning was the word, and the word was with God, and the word was God.”

Logos simply exists, all times, but by taking on flesh enters into time, interacts with time, bringing light into time, whereas before there was darkness in time. Darkness, time, yields to lightness, eternity. Ignorance yields to knowledge. Time is darkness because we cannot see what lies ahead. The future is unknown, and the past a memory. The present is a brief momentary anticipation of what might be. But if light enters darkness, if timeless enters time, then the path forward is brightened, made aware to us, lighting the way in the darkness. The future, always dark, is opened to light, and complete ignorance gives way to some knowledge of what will be. Not what might be. Because the night implies ignorance, implies that we are still guessing based on experience. No, now we know what will be thanks to the light.

All cultures have struggled to know the Logos. Polytheistic peoples conceived of a divinity that was inherent in nature, controlling all things, encompassing past, present, and future. The Hebrews identified it as Yahweh. The Greeks as the mind, the infinite, the good—the Logos. Asian philosophy called it the Way, the source, the Brahma. Christianity offers a unique perspective, of a transcendent that acts in time, subtly, upon the self, connecting the self to the transcendent—a direct physical and spiritual connection.

As for me, in my teaching and writing, I prefer to stay with Ante Christos and Anno Domini (not BCE/CE)—for how can time be truly understood without the incarnation, the Logos becoming flesh?