Meaning of BC and AD -the Surprising Back Story

BC and AD Timeline

Our calendar points to the birth of Jesus Christ -the most important person in all of history. It is divided into two sections -BC and AD.

What does BC and AD mean?

BC and AD are the terms used to describe the years “Before Christ” (BC means before Christ) and “AD” (In the Year of Our Lord).

AD stands for the years after Jesus Christ was born. BC stands for the years before the birth of Christ. There is no year zero, so there is only the year 1 BC followed by AD 1.

Meaning of BC

What does BC and AD stand for? A lot of people want to know.

And why do we use AD and BC?

While the initials BC (for Before Christ) are clearly English, AD comes from the Latin phrase Anno Domini.

“Before Christ” hints at the expectation in all of Israel of a coming Messiah, since there were many prophecies dating hundreds of years before Christ’s birth in Bethlehem.

One of those prophecies even named Bethlehem as the birthplace of the Messiah (the Hebrew word for Christ).

See the Old Testament prophecy and learn of the New Testament fulfillment at this post “Jesus’ Many Blatant Claims to be God.” There is ample literary (Biblical and extra-Biblical) and historical evidence that Jesus Christ is in fact God.

Meaning of AD

AD comes from the words Anno Domini, which are translated “In the Year of Our Lord” but there’s more to the meaning of BC and AD we’ll get to in a little bit.

By convention, here is how the years are said and written. For instance, here’s how this convention looks in writing: 454 BC and AD 1900.

BC always comes after the year, and AD comes before the year.

What Year is BC and AD?

When we talk about the years BC, they go backward from year 0. So the BC years get bigger as you go to the left on a timeline.

The AD years go forward to the right.

Of course, our system of using BC notation didn’t come about until centuries after the fact.

There’s no way folks in those days could have known they were living in the days of having the years go backward!

In most everyday communication, we don’t even use AD. We will just list the year as part of the date when we record day/month/year.

We use BC if we are talking about something that happened a really long time ago.

In normal conversation, it doesn’t come up too much.

But you can’t ignore the fact that the AD years started sometime. And there had to be a reason for it!

BC and AD Meaning
The Dividing Line of World History

What does the Latin Phrase Anno Domini Mean?

Anno is a lot like our English word Annual, which denotes a year. Domini means Lord (who dwells in dominion over all creation).

But AD is actually an abbreviation of the original term, which was quite a bit longer.

The entire original Latin phrase is “Anno Domini nostri Jesu” which translates as “In the year of our Lord Jesus Christ.”

This explains why AD is regarded as meaning “In the year of our Lord.”

Some folks guess AD stands for “After Death.”

But this meaning is impossible for AD. If it were true, there would be an approximate 33-year gap between BC and AD, which would be unworkable.

Another thing to consider is the abundant and dramatic historical and literary evidence of Jesus’ resurrection. 

Jesus’ death is a very important historical fact.

But the many overwhelming historical facts surrounding his resurrection make Jesus’ factual return to life after a horrible death very compelling.

It’s interesting to note the Gregorian calendar and the AD notation are not essential to the Christian faith and are not part of Biblical teachings.

BC and AD do not appear in the Bible. They do make it much easier to understand history, though!

So how did BC and AD happen?

The calendar we use today is a solar calendar.

It’s called the Gregorian calendar. It begins at the same place every year in the earth’s orbit around the sun.

It has become the world’s standard calendar.

But the calendar of the ancients was a lunar calendar –based on the moon’s orbit around the earth.

The Jewish calendar –still in use today- is a great example of a lunar calendar. So is the Chinese lunar calendar.

This lunar system was fine in the early years of human history when everyone was looking forward.  But in later years it made the historian’s job difficult.

There was no direct record of the years, so if a historian needed to calculate the date of some important event, it was very hard to do.

And as western culture advanced, it became more important for commercial reasons to schedule events for future dates as well.

 A change was in order, so an industrious Roman monk of Scythian origin named Dionysius Exiguus devised this new system in 525 AD.

Dionysius had a great reputation for scholarship. He was known for making translations of many important works from Greek into Latin for the Pope.

The then-current calendar system used data from the era of Diocletian. Dionysius didn’t want to give glory to Diocletian, a bloodthirsty Roman Emperor who had brutally persecuted and murdered Christians.

Dionysius did his work over 500 years after the birth of Christ and left no record of how he made the calculations.

Later scholars found he was off by a few years, so the birth of Christ is currently listed as ~4-6 BC. Dionysius’ small error is not a theological issue.

When Was AD First Used?

The birth of Christ remains the dividing line of world history just as he intended.

It took several hundred years for Dionysius’ work to catch on –one nation at a time- until the entire world accepted his calendar system.

The first written records using this notation were by the English Priest Bede (Saint Venerable) who made numerous notations in 679, 692, 697, etc.

Why Do We Use BCE and CE?

[People Also Ask: “What is BC and AD now called?]

BCE stands for “Before the Common Era” (Before the Current Era) and CE stands for “Common Era” (Current Era) and both are substitutes for BC and AD. These terms date back to as early as the 18th century.

BCE and CE were popularized by people who were not Christians.

They noted the very Christian nature of the BC and AD and that saying AD was acknowledging the Lordship of Jesus Christ.

Not everybody is willing to do that, so the alternates allow them to use terms that seem more religiously neutral.

But it’s apparent to all that there must be a reason for the divide between BC and AD. And Christians can accept the usage of BCE and CE by unbelievers without taking offense.

But the reason for this dividing line is the birth of Jesus Christ. There’s just no avoiding it.

See my post “What Does INRI Mean on the Cross of Jesus?” for more insight into the Kingship of Jesus Christ.

We could easily say BCE and CE refer to “Before the Christian Era” and “Christian Era” since this dating system corresponds directly to the birth of Christ.

Birth Date of Jesus

In ancient times, the calendar began at the Regnal year one (first year of their reign) at the coronation (crowning) of every new monarch.

So for example, we read about the history of the kings of Israel in the Old Testament, and there are references like this: “In the eighteenth year of King Jeroboam, Abijah began to reign over Judah.” 2 Chronicles 13:1

The New Testament reads the same way “In the fifteenth year of the reign of Tiberius Caesar…” (Luke 3:1a, ESV)

So history began anew with the coronation of a new king.

This is why we can pinpoint the birth of Christ down to a year. The Bible tells us the year in the terms of those days.

The equivalent Hebrew year of Jesus’ birth (~4 BC) would have been ~3756-3757.

When Jesus Christ was born, he was immediately recognized as King by the Magi.

Now after Jesus was born in Bethlehem of Judea in the days of Herod the king, behold, wise men from the east came to Jerusalem, saying, “Where is he who has been born king of the Jews? For we saw his star when it rose and have come to worship him.” Matthew 2:1-2, ESV

Now we hear of the Magi and see the 3 men on camels in the nativity scenes and think it looks cute under the Christmas tree.

But the Magi were powerful and influential men from a priestly caste of Persia who were not to be trifled with.

The genealogy of Jesus would have been on scrolls in the temple so it was verifiable.

And when the temple was destroyed in 70 AD, so were the genealogical records. So any later claim by another cannot be proven.

Jesus Christ remains King of the Jews (Matthew 27:37), and when he returns he will assert his kingship over the whole world.

How appropriate then, that we mark the years since his birth as the years of his reign just as was done during ancient times for the earthly kings.

Jesus’ birth lies at the horizontal intersection of world history. His death and resurrection lie at the vertical intersection of world history.

This intersection of the horizontal and vertical are emblematic of his bridging the gap from man-to-man (Jesus is 100% man) and God-to-man (Jesus is 100% God).

Is there a difference between God and Jesus? See my post “The Real Difference Between God and Jesus.

This is a reminder of the question asked of Jesus by a lawyer:

“Teacher, which is the great commandment in the Law?”

Jesus’ answer is known as the Great Commandment:

37 And he said to him, “You shall love the Lord your God with all your heart and with all your soul and with all your mind. 38 This is the great and first commandment. 39 And a second is like it: You shall love your neighbor as yourself. 40 On these two commandments depend all the Law and the Prophets.” Mark 22:36-40, ESV

And that is the back story that changed the world.

Is your Faith Founded on Fact? Have you committed to follow Jesus?

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