A.D to C.E.: The Common Dating Terms in European History

Pope Gregory XIII
Pope Gregory XIII of Gregorian Calendar Fame. Smithsonian Institution Libraries, Public Domain

Readers of works on European history (or, indeed, newspapers and pretty much anything else) may notice there are two competing dating systems, using short abbreviations: the A.D. and B.C. versus the C.E. and B.C.E. The former is a religiously motivated way of dividing two major time periods in human history, while the latter is a modern, non-denominational way. The actual year zero is the same in both systems, as are the years, so in practice it doesn’t make much difference, and year zero is so well engrained no attempt to change it has ever succeeded in the western world (although they tried in French Revolution, for one example.


A.D. is an abbreviation for Anno Domini - Latin for The Year Of Our Lord - used in the Gregorian Calendar to refer to the current era. A date such as 1945 A.D. literally means 'the 1945th year of our lord', the lord in question being Jesus Christ, providing a religious context and clearly distinguishing the time from an earlier era, where B.C is used instead. The use of A.D. was popularised by Bede, but is increasingly replaced with C.E.

Modern historical research suggests the current A.D. date is actually wrong, as Jesus was born 4-7 years earlier than the year 1 date the Gregorian calendar works from. However, in the modern age the actual meaning of A.D. is widely forgotten or misunderstood and the term simply signifies a different era from B.C. There is a common misuse as 'After Death'. As A.D. refers to Christ's birth, not his death, this expansion is wholly erroneous.


B.C is an abbreviation for 'Before Christ', used in the Gregorian calendar (in turn used widely around the world, including in the US, Canada and Britain) to refer to the era before the birth of Jesus Christ, the central Christian figure. While the use of B.C. is believed to originate with the Bede in the eighth century, it only became popular in the modern era. Most of ancient history is B.C., including the classical age of the Greeks and many of the Roman’s more famous exploits. Increasingly replaced with B.C.E.


C.E. is an abbreviation for 'Common Era', a non-religious alternative to the use of A.D. in designating the second period of the Gregorian calendar, our current era. With the Gregorian system heavily entrenched in the west and increasingly accepted across the world 'A.D.', which stands for Anno Domini ('The Year Of Our Lord') is increasingly seen as inappropriate given the majority who have different, if any, 'lords'. However, Christians are able to retain their reference to Jesus by substituting Christian for Common: ‘Christian Era’.

By using loose and non-thematic terms C.E. has the benefit of not being wrong, unlike A.D. due to Jesus being born several years before the 1. A.D. start point.


B.C.E is an abbreviation for 'Before Common Era', a non-religious alternative to the use of B.C. in designating the first period of the Gregorian calendar, the era of prehistory and much of antiquity. The zero date for BCE is the same as BC; in fact all the dates remain the same (e.g. 367 BCE / CE.)
B.C.E is the partner of C.E. Unfortunately, the repetition of c and e means B.C.E can often be confused with C.E., especially by someone scanning quickly.

Is this important? It's easy to look at the fact both dating systems use the same zero date, and so have the same numbers for the same events, and conclude this is all pointless, why not just do the older system (I have actually been told this in response to the article.) But we live in a multi faith world where using 'the year of our lord' can be galling to many people, and the new system reflects a move to a broader, less restricted unit. It's also difficult to see the year 0 remaining the same in the long term, and as this is a history website we're talking really long term.