The idea to count years from the birth of Jesus Christ was first proposed in the year 525 by Dionysius Exiguus, a Christian monk. Standardized under the Julian and Gregorian calendars, the system spread throughout Europe and the Christian world during the centuries that followed. AD stands for Anno Domini, Latin for “in the year of the Lord”, while BC stands for “before Christ”.
https://www.druide.com/en/reports/bc-and-ad-bce-and-ce-whats-difference
In the 1980s we became more multifaith and politically correct and began using BCE/CE. CE means “common (or current) era”, and BCE means “before the common (or current) era”. Although these abbreviations are really not so new, dating from at least the early 1700s.
But 2020 has been such a significant year (for all the wrong reasons), that I’m thinking we should start again with BC/AC – Before COVID and After COVID. Here’s hoping that AC begins soon!
2022 Still waiting for AC…