Anno Domini

Anno Domini (AD), meaning ‘in the year of the Lord’, and Before Christ (BC), is the dating system applied to the Julian Calendar and Gregorian Calendar.
It was invented in 525 AD by an Eastern European monk from Scythia Minor in the Danube, called Dionysius Exiguus.

This is from the Latin, meaning the Era of the Martyrs, and is also known as Anno Diocletiana, meaning the Diocletian Era.
It was the dating method adopted by the Church of Alexandria and the Coptic Othodox Church of Alexandria.
Year 1 Anno Martyrium was the 28th November 284 Anno Domini, the start of Diocletian’s rule who was noted for the Diocletianic Persecution.

Anno Mundi (abbreviation A.M.) translates from the Latin as ‘In the year of the world’ meaning ‘in the year after Creation’.
The Byzantine Calendar was based on a Creation date of 1st September 5509 BC of the Julian Calendar.
The Hebrew Calendar is based on a slightly different Creation date of 6th October 4761 BC of the Julian Calendar.

Common Era (CE) and Before Common Era (BCE) is an alternative notation to the Anno Domini dating System.
It is applied to the Gregorian Calendar in the same way as Anno Domini (BC/ AD).
It was first used in 1615 CE in a book by the German Astronomer, Johannes Kepler and first used in publications in 1708, 1715 and 1759 CE
As the whole world now uses the Gregorian Calendar as an international standard, the neutral Common Era notation is often the preferred choice in academic and scientific publications.