Anno Domini
Anno Domini and
Before Christ are designations used to label or number years used with the Julian and Gregorian calendars. The term
Anno Domini is Medieval Latin, translated as
In the year of the Lord, and as
in the year of Our Lord.:782 It is sometimes specified more fully as
Anno Domini Nostri Iesu Christi. This calendar era is based on the traditionally reckoned year of the conception or birth of Jesus of Nazareth, with
AD counting years from the start of this epoch, and
BC denoting years before the start of the era. There is no year zero in this scheme, so the year AD 1 immediately follows the year 1 BC. This dating system was devised in 525, but was not widely used until after 800. The Gregorian calendar is the most widely used calendar in the world today. For decades, it has been the unofficial global standard, adopted for pragmatic interests of international communication, transportation, and commercial integration, and recognized by international institutions such as the United Nations and the Universal Postal Union.