Anno domini system of dating
Traditionally, English has copied Latin usage by placing the abbreviation before the year number for AD.
Since BC is not derived from Latin it is placed after the year number (for example: 68 BC, but AD 2011).
in 1505 for us) and on 12 April 1506, but not in 1505., and say that those who accept the story of the Massacre of the Innocents sometimes associate the star that led the Biblical Magi with the planetary conjunction of 15 September 7 BC or Halley's comet of 12 BC (less likely since comets were usually considered bad omens); even historians who do not accept the Massacre accept the birth under Herod as a tradition older than the written gospels.
The Jewish historian Josephus, in his Antiquities of the Jews (ca.
AD 93), indicates that Cyrenius/Quirinius' governorship of Syria began in AD 6, and that the census occurred sometime between AD 6—7,.
The Anno Domini dating system was devised in 525 by Dionysius Exiguus to enumerate the years in his Easter table.
His system was to replace the Diocletian era that had been used in an old Easter table because he did not wish to continue the memory of a tyrant who persecuted Christians.