Anno Domini (abbreviated as AD or A.D. sometimes found in the form Anno Domine) and Before Christ (abbreviated as BC or B.C.) are designations used to label or number years in the Julian and Gregorian calendars. The AD or the Christian calendar era is based on the traditionally reckoned year of the conception or birth of Jesus of Nazareth with AD counting years after the start of this epoch and BC denoting years before the start of the epoch. 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 8001 and even after that other systems were still widely used throughout Europe.

The Gregorian calendar is the most widely used calendar in the world today. For decades it has been the unofficial global standard recognized by international institutions such as the United Nations and the Universal Postal Union. Though the Western calendars spread around the world over the past four centuries as a result of western power in modern times the Gregorian calendar and AD year numbering has been adopted by many non-Western countries with no Christian heritage. It has been adopted for pragmatic interests of international communication transportation and commercial integration.2 It has also become a basis of scholarly dating.

The term Anno Domini is Medieval Latin translated as In the year of (the/Our) Lord.34:782 It is sometimes specified more fully as Anno Domini Nostri Iesu (Jesu) Christi ("In the Year of Our Lord Jesus Christ"). Because BC is the English abbreviation for Before Christ it is sometimes incorrectly concluded that AD means After Death5 i.e. after the death of Jesus. If that were true the thirty-three or so years of his life would not be in any era.67

Traditionally English has copied Latin usage by placing the abbreviation before the year number for AD.8 Since BC is not derived from Latin it is placed after the year number (for example: 68 BC but AD 2011). However placing the AD after the year number (as in "2011 AD") is also becoming common usage. 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).9 Anno Domini inscription at Carinthia cathedral Austria Contents 1 History 1.1 Birth of Jesus 1.2 Popularization 1.3 Change of year 1.4 Other eras 2 Common Era 3 No year zero 4 Controversy 5 Proposed reforms 6 See also 7 Notes and references 8 External links History

The Anno Domini dating system was devised in 525 by Dionysius Exiguus who used it to compute the date of the Christian Easter festival and to identify the several Easters in his Easter table but did not use it to date any historical event. 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. The last year of the old table Diocletian 247 was immediately followed by the first year of his table AD 532. When he devised his table Julian calendar years were identified by naming the consuls who held office that year he himself stated that the "present year" was "the consulship of Probus Junior" which was 525 years "since the incarnation of our Lord Jesus Christ".10 Thus Dionysius implied that Jesus' Incarnation occurred 525 years earlier without stating the specific year during which his birth or conception occurred. "However nowhere in his exposition of his table does Dionysius relate his epoch to any other dating system whether consulate Olympiad year of the world or regnal year of Augustus; much less does he explain or justify the underlying date."4:778

Blackburn & Holford-Strevens briefly present arguments for 2 BC 1 BC or AD 1 as the year Dionysius intended for the Nativity or Incarnation. Among the sources of confusion are:4:7789 In modern times Incarnation is synonymous with the conception but some ancient writers such as Bede considered Incarnation to be synonymous with the Nativity The civil or consular year began on 1 January but the Diocletian year began on 29 August There were inaccuracies in the list of consuls There were confused summations of emperors' regnal years Birth of Jesus See also: Nativity of Jesus and Chronology of Jesus

According to Doggett "Although scholars generally believe that Christ was born some years before AD 1 the historical evidence is too sketchy to allow a definitive dating".11 According to Matthew 2:112 and Matthew 2:1613 King Herod the Great was alive when Jesus was born and ordered the Massacre of the Innocents in response to his birth. Blackburn and Holford-Strevens fix King Herod's death shortly before Passover in 4 BC4:770 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.4:776

The Gospel of Luke states that Jesus was conceived during the reign of Herod the GreatLuke 1:5 (i.e. before 4 BC) while also stating that Jesus was born when Cyrenius (or Quirinius) was the governor of Syria and carried out the census of the Roman provinces of Syria and Iudaea.Luke 2:1-3 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 6-714 which is incompatible with a conception prior to 4 BC. On this point Blackburn and Holford-Strevens state that "St. Luke raises greater difficulty ... Most critics therefore discard Luke". Some scholars rely on John 8:5715: "thou are not yet fifty years old" to place Christ's birth c. 18 BC.4:776 Popularization

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 finished in 731. In this same history he also used another Latin term "ante vero incarnationis dominicae tempus" ("the time before the Lord's true incarnation") equivalent to the English "before Christ" to identify years before the first year of this era16 thus establishing the standard of not using a year zero17 even though he used zero in his computus. Both Dionysius and Bede regarded Anno Domini as beginning at the incarnation of Jesus but "the distinction between Incarnation and Nativity was not drawn until the late 9th century when in some places the Incarnation epoch was identified with Christ's conception i.e. the Annunciation on March 25" (Annunciation style).4:881 On the continent of Europe Anno Domini was introduced as the era of choice of the Carolingian Renaissance by Alcuin. Its endorsement by Emperor Charlemagne and his successors popularizing the usage of the epoch and spreading it throughout the Carolingian Empire ultimately lies at the core of the system's prevalence. According to the Catholic Encyclopedia popes continued to date documents according to regnal years for some time but usage of AD gradually became more common in Roman Catholic countries from the 11th to the 14th centuries.18 Eastern Orthodox countries only began to adopt AD instead of the Byzantine calendar in 1700 when Russia did so with others adopting it in the 19th and 20th centuries. Even though Anno Domini was in widespread use by the 9th century Before Christ (or its equivalent) did not become common until much later. Bede used the expression "anno igitur ante incarnationem Dominicam" (before the Incarnation of the Lord) twice. "Anno an xpi nativitate" (before the birth of Christ) is found in 1474 in a work by a German monk.19 In 1627 the French Jesuit theologian Denis Ptau (Dionysius Petavius in Latin) with his work De doctrina temporum popularized the usage ante Christum (Latin for "Before Christ") to mark years prior to AD.202122 Change of year When the reckoning from Jesus' incarnation started replacing the previous dating systems in western Europe different people chose different Christian feast days to begin the year: Christmas Annunciation or Easter. Thus depending on the time and place year number changed on different days which created slightly different styles in chronology:23 from 25 March 753 AUC (today in 1 BC) i.e. from the incarnation of Jesus. That first "Annunciation style" appeared in Arles at the end of the 9th century then spread to Burgundy and northern Italy. It was not commonly used and was called "calculus pisanus" since it was adopted in Pisa and survived there till 1750. from 25 December 753 AUC (today in 1 BC) i.e. from the birth of Jesus. It was called "Nativity style" and had been spread by the Venerable Bede together with the Anno Domini in the early Middle Ages. That reckoning of the year of Grace from Christmas was used in France England and most of western Europe (except Spain) till the 12th century (when it was replaced by Annunciation style) and in Germany till the second quarter of the 13th century. from 25 March 754 AUC (today in AD 1). That second "Annunciation style" may have originated in Fleury Abbey in the early 11th century but it was spread by the Cistercians. Florence adopted that style in opposition to the one of Pisa so it got the name of "calculus florentinus". It soon spread in France and also in England where it became common in the late 12th century and lasted until 1751. from Easter starting in 754 AUC (AD 1). That "mos gallicanus" bound to a movable feast was introduced in France by king Philip Augustus (1165-1180-1223) maybe to establish a new style in the provinces reconquered over England. However it never spread beyond the ruling lite. With those various styles the same day could in some cases be dated in 1099 1100 or 1101. The Annunciation style also caused a major problem: in some years there was no Easter and in other years that feast was celebrated twice; for example Easter occurred on 23 March 1504 (i.e. in 1505 for us) and on 12 April 1506 but not in 1505.24 Other eras Further information: Calendar era During the first six centuries of what would come to be known as the Christian era European countries used various systems to count years. Systems in use included consular dating imperial regnal year dating and Creation dating. Although the last non-imperial consul Basilius was appointed in 541 by Emperor Justinian I later emperors through Constans II (641668) were appointed consuls on the first 1 January after their accession. All of these emperors except Justinian used imperial post-consular years for all of the years of their reign alongside their regnal years.25 Long unused this practice was not formally abolished until Novell XCIV of the law code of Leo VI did so in 888. Another calculation had been developed by the Alexandrian monk Annianus around the year AD 400 placing the Annunciation on 25 March AD 9 (Julian)eight to ten years after the date that Dionysius was to imply. Although this Incarnation was popular during the early centuries of the Byzantine Empire years numbered from it an Era of Incarnation were only used and are still only used in Ethiopia accounting for the eight- or seven-year discrepancy between the Gregorian and the Ethiopian calendars. Byzantine chroniclers like Maximus the Confessor George Syncellus and Theophanes dated their years from Annianus' creation of the World. This era called Anno Mundi "year of the world" (abbreviated AM) by modern scholars began its first year on 25 March 5492 BC. Later Byzantine chroniclers used Anno Mundi years from 1 September 5509 BC the Byzantine Era. No single Anno Mundi epoch was dominant throughout the Christian world. Eusebius of Caesarea in his Chronicle used an era beginning with the birth of Abraham dated in 2016 BC (AD 1 2017 Anno Abrahami).26 Spain and Portugal continued to date by the Era of the Caesars or Spanish Era which began counting from 38 BC well into the Middle Ages. In 1422 Portugal became the last Catholic country to adopt the Anno Domini system.18 The Era of Martyrs which numbered years from the accession of Diocletian in 284 who launched the last yet most severe persecution of Christians was used by the Church of Alexandria and is still used officially by the Coptic church. It also used to be used by the Ethiopiandisambiguation needed church. Another system was to date from the crucifixion of Jesus Christ which as early as Hippolytus and Tertullian was believed to have occurred in the consulate of the Gemini (AD 29) which appears in the occasional medieval manuscript. Common Era Main article: Common Era Anno Domini is sometimes referred to as the Common Era Christian Era or Current Era (abbreviated as C.E. or CE). CE is often preferred by those who desire a term not explicitly related to Christian conceptions of time.2728 For example Cunningham and Starr (1998) write that "B.C.E./C.E. do not presuppose faith in Christ and hence are more appropriate for interfaith dialog than the conventional B.C./A.D." Upon its foundation the Republic of China adopted the Western calendar in 1912 and the translated term was (lit. Western Era). Later in 1949 the People's Republic of China reiterated the use of the Gregorian calendar and accepted the term gngyun ( lit. Common Era). Regardless of name the dating scheme remains the same. No year zero Further information: 0 (year) Astronomical year numbering and Millennium In the AD year numbering system whether applied to the Julian or Gregorian calendars AD 1 is preceded by 1 BC. There is no year "0" between them. Because of this most experts agree that a new century begins in a year with the last digits being "01" (1801 1901 2001); new millennia likewise began in 1001 and 2001. A common misconception is that centuries and millennia begin when the trailing digits are zeroes (1800 1900 2000 etc.);1 moreover this convention was widely used to celebrate the new millennium in the year 2000. For computational reasons astronomers and the ISO 8601 standard use a time scale (astronomical year numbering) in which AD 1 year 1 1 BC year 0 2 BC year 1 etc.29 Controversy Some feel that using the phrase "Year of our Lord"3031 or basing the world's dating system on the life of Jesus are forms of bias towards the Christian religion.32 Attempts to use the more secular year designations BCE (Before the Common Era) and CE (Common Era) have also stirred debate in some countries.3334 Proposed reforms The following are proposed reforms of the Gregorian calendar: Holocene calendar International Fixed Calendar (also called the International Perpetual calendar) World Calendar World Season Calendar Leap week calendars Pax Calendar Common-Civil-Calendar-and-Time Symmetry454 See also Calendar Notes and references Notes a b Teresi Dick (July 1997). "Zero". The Atlantic. http://www.theatlantic.com/past/docs/issues/97jul/zero.htm.  Eastman Allan. "A Month of Sundays". Date and Time. http://www.timeanddate.com/newsletter/all-the-time/a-month-of-sundays5.html. Retrieved 4 May 2010.  "Anno Domini". Merriam Webster Online Dictionary. Merriam-Webster. 2003. http://www.m-w.com/dictionary/Anno%20Domini. Retrieved 3 February 2008. "Etymology: Medieval Latin in the year of the Lord".  a b c d e f g Blackburn Bonnie; Leofranc Holford-Strevens (2003). The Oxford companion to the Year: An exploration of calendar customs and time-reckoning. Oxford University Press. ISBN 0-19-214231-3.  (reprinted & corrected originally published 1999) What is the meaning of BC and AD (B.C. and A.D.) Got Questions Ministries. Retrieved 2 February 2010. Donald P. Ryan (2000) 15. Paul Brians. (n.d.). "A.D." in Common Errors in English Usage. (Washington State University faculty website.) Retrieved 2 February 2010 This convention comes from grammatical usage. Anno 500 means "in the year 500"; anno domini 500 means "in the year 500 of Our Lord". Just as "500 in the year" is not good English syntax neither is 500 AD; whereas "AD 500" preserves syntactic order when translated. Chicago Manual of Style 1993 p. 304. Nineteen year cycle of Dionysius Introduction and First Argumentum. Doggett 1992 579. Matthew 2:1 Matthew 2:16 Flavius Josephus. The Antiquities of the Jews Book 18 Chapters 1-2. Josephus indicates that the census under Cyrenius (i.e. Quirinius) occurred in the 37th year after Octavian's (i.e. Gaius Julius Caesar Augustus') victory over Marc Antony at Actium which secular historical records date to September 2 31 BCE. Therefore 31 BCE + 37 years 6-7 CE. John 8:57 Bede 731 Book 1 Chapter 2 first sentence. Compare Bede 731 Book 1 Chapter 2 first sentence with Chapter 3. a b Gerard 1908 Werner Rolevinck in Fasciculus temporum (1474) used Anno an xpi nativitatem (in the year before the birth of Christ) for all years between creation and Jesus. "xpi" is the Greek in Latin letters which is a cryptic abbreviation for christi. This phrase appears upside down in the centre of recto folios (right hand pages). From Jesus to Pope Sixtus IV he usually used Anno christi or its cryptic form Anno xpi (on verso foliosleft hand pages). He used Anno mundi alongside all of these terms for all years. Steel Duncan (2000). Marking time: the epic quest to invent the perfect calendar. p. 114. ISBN 9780471298274. http://books.google.com/idfsniqV-FJoC&pgPA111#vonepage&q1627. Retrieved 1 June 2010.  Hunt Lynn Avery (2008). Measuring time making history. p. 33. ISBN 9789639776142. http://books.google.com/idA6nrL1XxpGYC&pgPA33&lpgPA33&dqpetau+%22ante+Christum%22&qpetau%20%22ante%20Christum%22. Retrieved 1 June 2010.  Petau Denis (1758). search for "ante Christum" in a 1748 reprint of a 1633 abridgement entitled Rationarium temporum by Denis Petau. http://books.google.com/idRRv0NEpl-oC&pgPA46&lpgPA46&dqpetau+%22ante+Christum%22&qante%20Christum. Retrieved 1 June 2010.  C.R. Cheney A Handbook of Dates for students of British history Cambridge University Press 1945-2000 pp. 8-14. Easter Sunday/Jewish Passover calculator Roger S. Bagnall and Klaas A. Worp Chronological Systems of Byzantine Egypt Leiden Brill 2004. Alfred von Gutschmid Kleine Schriften F. Ruehl Leipzig 1889 p.433. Robinson B.A. (20 April 2009). "Controversy over the use of "CE/BCE" or "AD/BC" dating notation". ReligiousTolerance.org. http://www.religioustolerance.org/ce.htm.  William Safire (17 August 1997). "On Language: B.C./A.D. or B.C.E./C.E.". The New York Times Magazine. http://www.nytimes.com/1997/08/17/magazine/bc-ad-or-bce-ce.htmlpagewanted1.  To convert from a year BC to astronomical year numbering reduce the absolute value of the year by 1 and prefix it with a negative sign (unless the result is zero). For years AD omit the AD and prefix the number with a plus sign (plus sign is optional if it is clear from the context that the year is after the year 0). Doggett 1992 p. 579 "Trinity University trustees keeping 'Year of our Lord' on diplomas". KENS 5 TV. 22 April 2010. http://www.kens5.com/news/Trinity-trustees-keeping-Year-of-our-Lord-on-diplomas-91854709.html.  Mohler Jr. R. Albert (21 April 2010). "'The Year of Our Lord' - Diploma Trouble in Texas". The Christian Post. http://www.christianpost.com/article/20100421/the-year-of-our-lord-diploma-trouble-in-texas/.  Juggie Naran (15 May 2005). "Do we get rid of BC and AD". Sunday Tribune.  "Historical Designations Controversy". WBKO News (Associated Press). 14 June 2006. http://www.wbko.com/news/headlines/3054266.html.  Michael Jennings (31 May 2006). "Kentucky Asks What Year Is It: After evolution fights comes dispute over A.D. vs. C.E.". Christianity Today. http://www.christianitytoday.com/ct/2006/mayweb-only/122-32.0.html.  References Abate Frank R(ed.) (1997). Oxford Pocket Dictionary and Thesaurus (American ed.). New York: Oxford University Press. ISBN 0-19-513097-9.  Bede. (731). Historiam ecclesiasticam gentis Anglorum. Accessed 7 December 2007. Chicago Manual of Style (2nd ed.). University of Chicago. 1993. ISBN 022610389-7.  Cunningham Philip A; Starr Arthur F (1998). Sharing Shalom: A Process for Local Interfaith Dialogue Between Christians and Jews. Paulist Press. ISBN 0-8091-3835-2.  Declercq Georges (2000). Anno Domini: The origins of the Christian era. Turnhout: Brepols. ISBN 2-503-51050-7.  (despite beginning with 2 it is English) Declercq G. "Dionysius Exiguus and the Introduction of the Christian Era". Sacris Erudiri 41 (2002): 165246. An annotated version of part of Anno Domini. Doggett. (1992). "Calendars" (Ch. 12) in P. Kenneth Seidelmann (Ed.) Explanatory supplement to the astronomical almanac. Sausalito CA: University Science Books. ISBN 0-935702-68-7. Gerard J. (1908). "General Chronology". In The Catholic Encyclopedia. New York: Robert Appleton Company. Retrieved 16 July 2008 from New Advent: http://www.newadvent.org/cathen/03738a.htm Richards E. G. (2000). Mapping Time. Oxford: Oxford University Press. ISBN 0-19-286205-7.  Riggs John (January 2003). "Whatever happened to B.C. and A.D. and why". United Church News. http://www.ucc.org/ucnews/janfeb03/whatever-happened-to-bc-and.html. Retrieved 19 December 2005.  Ryan Donald P. (2000). The Complete Idiot's Guide to Biblical Mysteries. Alpha Books. p. 15. ISBN 002863831X.  External links Look up AD or Anno Domini in Wiktionary the free dictionary. 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