When writing about historical figures or events, we often need to use BC and AD, or BCE and CE. How can you use them correctly?

Firstly, both systems count years from the birth of Jesus Christ, following the Gregorian calendar. AD and CE mean before the birth date of Jesus, and BC and BCE mean after the birth date of Jesus.

BC and AD were used earlier in the year 525 by a Christian monk. AD stands for “Anno Domini”, which is Latin and means “in the year of the Lord”; BC stands for “Before Christ”. BCE and CE were used in the early 1700s, mostly in science and academia, becoming widespread for the reason of religious neutrality. CE stands for “commoon era”, and BCE stands for “before common era”.

At present, both systems are used widely. When using it, make sure to use BC and AD, or BCE and CE; don’t mess them up.

Here are some conventions to follow:

  • BC should appear after the numerical year: 900 BC
  • Ad should appear before the numerical year: AD 510
  • BCE should appear after the numerical year: 510 BCE
  • CE should appear after the numerical year: 510 CE

You can use periods after the letters: 1100 B.C., A.D. 1088. That is a style issue. If only you keep consistency in your writing, it will be fine.