Home   Calendar   CE and BCE

Common Era (CE) and Before Common Era (BCE)

The letters CE or BCE in conjunction with a year mean after or before year 1.

Tourists visit the ruins of the ancient city of Pompeii, Italy.

Pompeii was founded 600–700 BCE.


  • CE is an abbreviation for Common Era.
  • BCE is short for Before Common Era.

The Common Era begins with year 1 in the Gregorian calendar.

Instead of AD and BC

CE and BCE are used in exactly the same way as the traditional abbreviations AD and BC.

  • AD is short for Anno Domini,
    Latin for in the year of the Lord.
  • BC is an abbreviation of Before Christ.

Because AD and BC hold religious (Christian) connotations, many prefer to use the more modern and neutral CE and BCE to indicate if a year is before or after year 1.

According to the international standard for calendar dates, ISO 8601, both systems are acceptable.

Both in Use for Centuries

The Anno Domini year-numbering system was introduced by a Christian monk named Dionysius Exiguus in the 6th century. The year count starts with year 1 in the Gregorian calendar. This is supposed to be the birth year of Jesus, although modern historians often conclude that he was born around 4 years earlier.

The expression Common Era is also no new invention, it has been in use for several hundred years. In English, it is found in writings as early as 1708. In Latin, the term "vulgaris aerae" (English, Vulgar Era) was used interchangeably with "Christian Era" as far back as in the 1600s.

More and More Use CE/BCE

What is relatively new is that more and more countries and their educational institutions have officially replaced the traditional abbreviations AD/BC with CE/BCE.

England and Wales introduced the CE/BCE system into the official school curriculum in 2002, and Australia followed in 2011. More and more textbooks in the United States also use CE/BCE, as well as history tests issued by the US College Board.

Avoid Confusion

A year listed without any letters is always Common Era, starting from year 1.

Adding CE or BCE after a year is only necessary if there is room for misunderstanding—for example, in texts where years both before and after year 1 are mentioned.

For instance, Pompeii, Italy (see image) was founded around 600–700 BCE and was destroyed when Mount Vesuvius erupted in 79 CE.

Topics: Calendar, Dates