The Gregorian calendar is the most widely used calendar in the world today.
For decades, it has been the unofficial global standard, adopted in the pragmatic interests of international communication, transportation, and commercial integration, and recognized by international institutions such as the United Nations.
However, BC is placed after the year number (for example: AD 2018, but 68 BC), which also preserves syntactic order.
The abbreviation is also widely used after the number of a century or millennium, as in "fourth century AD" or "second millennium AD" (although conservative usage formerly rejected such expressions).
The Anglo-Saxon historian the Venerable Bede, who was familiar with the work of Dionysius Exiguus, used Anno Domini dating in his Ecclesiastical History of the English People, completed in 731.