Changes

In general, English usage follows Latin by placing the abbreviation ''before'' the year number for AD, but ''after'' the year number for BC, although there are several exceptions to the first part of this principle. Constructions such as "the fourth century AD" are widely accepted, but using full month-and-day with '''AD''' is not (one does not write "September 11, 2001, AD").

In general, English usage follows Latin by placing the abbreviation ''before'' the year number for AD, but ''after'' the year number for BC, although there are several exceptions to the first part of this principle. Constructions such as "the fourth century AD" are widely accepted, but using full month-and-day with '''AD''' is not (one does not write "September 11, 2001, AD").

[[BC]] is an English [[initialism]] meaning "Before Christ" and always is the last element. If the context does not otherwise indicate we are in such times, one is obligated to use the form. One can use it with full explicit dates, e.g., "Julius Caesar was killed March 15, 44 BC".

[[BC]] is an English [[initialism]] meaning "Before Christ" and always is the last element. If the context does not otherwise indicate we are in such times, one is obligated to use this form. One can use it with full explicit dates, e.g., "Julius Caesar was killed March 15, 44 BC".

* Though the Anno Domini dating system was devised in 525, it was not until the eighth century that the system began to be adopted in Western Europe. [http://www.absoluteastronomy.com/topics/Anno_Domini]

* Though the Anno Domini dating system was devised in 525, it was not until the eighth century that the system began to be adopted in Western Europe. [http://www.absoluteastronomy.com/topics/Anno_Domini]