People in the Western world debate many things, from whether cheesecake is actually a cake to which airplane seat is the best—aisle or the window? What year it is generally does not fall into the category of debated facts. However, how to refer to said year and the past years from ancient history—BC and AD or BCE and CE—does.
Both sets of abbreviations have history. One set has existed for thousands of years while the other has existed for hundreds. Before deciding on which one to use, or if you’re wondering why there’s a debate in the first place, it’s important to know how each came about.
What do BC and BCE mean?
The abbreviation BC stands for “before Christ,” while AD stands for annō Dominī, which translates to “in the year of the lord.” The lord that’s being referenced, as BC hints at, is Jesus Christ.
The alternative to using BC and AD would be to use BCE, which means “before Common Era,” and CE, which means “Common Era.” Despite removing Christianity from the name, BCE and CE are still tied to the original Christian idea of BC and AD. That’s because all of these abbreviations use the same date as the starting point for when to count forward and when to count backward, meaning the date is the same whether you use the secular or Christian abbreviation.
Though the date sounds fixed—there was a “before” time and an “after” time—it’s a little more complicated than that. And to understand why we use BC or BCE, we’ve got to dive into the past. Time for some History (and Religion) 101.
Where do BC and AD come from?
Before the creation of BC and AD, people marked the years by who was in power. Ancient Romans named their years based off of how long a consul or emperor had ruled, while Egyptians similarly counted their years based on the years a king ruled. Yet in the sixth century (at least what we’d call the sixth century today), people in power wanted a consistent way to keep track of the years so that everyone was on the same page. In particular, Christian leaders wanted a set and agreed upon date for Easter.
Enter the monk Dionysius Exiguus, who lived in what is today Romania and Bulgaria. In the year 525, Dionysius started a movement to define time as “before Christ” and “after Christ” rather than number the years based on when a Roman emperor ruled. It didn’t hurt that the emperor who the years were named after in the time of Dionysius, Diocletian, persecuted early Christians. Dionysius’s annō Dominī set the standard for “the year of our lord” rather than the year of the emperor.
Dionysius never recorded how he decided on the date of Jesus Christ’s birth. Some scholars think he used astrological signs, while others believe he based his assertion on the Bible. The gospels don’t necessarily agree on that date, though, with the Gospel of Matthew noting that Jesus was born when Herod the Great, who died in 4 BCE, was in power, while the Gospel of Luke notes the birth was when Quirinius was governor of Syria around 6 CE. What we do know, however, is that Dionysius was successful in promoting his timeline, and it became the standard used to this day.
The years before what Dionysius set as Jesus’s birthday weren’t universally named for another couple hundred years. An English monk named Bede came up with the idea of BC, or “Before Christ,” in 731. Suddenly, there was a systematic way to label the years that happened after the year that Dionysius declared Jesus was born, and it counted backward rather than forward.
Of note: zero never made it into the equation. The concept of zero didn’t make it to Europeans until the 1100s.
Regardless of the confusion on dates and the missing zero, the BC and AD way of labeling time caught on thanks to Charlemagne, who ruled much of Western Europe in the late 700s. It was the standard when the Gregorian calendar—which replaced the Julian calendar and is still used today—was made in 1582. BC and AD were also used by the International Organization for Standardization in 1988 when setting the years to be used for international business and government.
Where do BCE and CE come from?
These abbreviations are tied to BC and AD without being explicitly tied to Christianity as well. BCE (Before Common Era) and CE (Common Era) have been used since the early 1700s by various writers and English language dictionaries. There was a secular term before these came into common use as well: Vulgar Era, which was used in the early 1600s—a time when vulgar meant ordinary or common.
Even though both abbreviations refer to the same dates, there is a reason to use BCE and CE over BC and AD. For one, people who aren’t Christian can use the abbreviations freely without contradicting their own beliefs by simply stating the year. Secondly, the historical evidence isn’t quite there for how Dionysus picked the year Jesus was born, so it’s a questionable starting date when set to Jesus’s birth year.
The likelihood of the dates being adjusted to better match historical records isn’t great. If you thought writing the year right when the calendar changes is tough now, just imagine how hard it would be for everyone to adjust if things were changed to account for historical accuracy or to add a year zero.
Ultimately, using BCE and CE gets around the issue of labeling years in accordance with a single religion while also keeping the dates as we know them.