The terms ANNO DOMINI (AD) and BEFORE CHRIST (BC) are used to
label or number years in the Julian and Gregorian calendars . The term
_anno Domini_ is
Medieval Latin and means "in the year of the Lord",
but is often translated as "in the year of our Lord".
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
Dionysius Exiguus of
Scythia Minor , but was not widely used
until after 800.
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 .
Traditionally, English followed
Latin usage by placing the "AD"
abbreviation before the year number. However, BC is placed after the
year number (for example: AD 2017, 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). Because BC is the English abbreviation for _Before
Christ_, it is sometimes incorrectly concluded that AD means _After
Death_, i.e., after the death of Jesus. However, this would mean that
the approximate 33 years commonly associated with the life of Jesus
would not be included in either of the BC and the AD time scales.
Terminology that is viewed by some as being more neutral and
inclusive of non-Christian people is to call this the Current or
Common Era (abbreviated as CE), with the preceding years referred to
as Before the Common or Current
Era (BCE). Astronomical year numbering
ISO 8601 avoid words or abbreviations related to Christianity, but
use the same numbers for AD years.
* 1.1 Popularization
* 1.2 Change of year
* 2 Historical birth date of
* 3 Other eras
* 4 CE and BCE
* 5 No year zero / Start and end of a century
* 6 See also
* 7 Notes
* 8 References
* 8.1 Citations
* 8.2 Sources
* 9 External links
The _Anno Domini_ dating system was devised in 525 by Dionysius
Exiguus to enumerate the years in his
Easter table . His system was to
Diocletian era that had been used in an old
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". 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
Olympiad , year of the world, or regnal year of Augustus;
much less does he explain or justify the underlying date."
Bonnie J. Blackburn and
Leofranc 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:
* 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 (30 August in the year before a Julian leap
* There were inaccuracies in the list of consuls
* There were confused summations of emperors' regnal years
It is not known how Dionysius established the year of Jesus's birth.
Two major theories are that Dionysius based his calculation on the
Gospel of Luke, which states that
Jesus was "about thirty years old"
shortly after "the fifteenth year of the reign of Tiberius Caesar",
and hence subtracted thirty years from that date, or that Dionysius
counted back 532 years from the first year of his new table. It is
convenient to initiate a calendar not from the very day of an event
but from the beginning of a cycle which occurs in close proximity. For
Islamic calendar begins not from the date of the
but rather weeks later, on the first subsequent occurrence of the
month of Muharram (corresponding to 16 July AD 622).
It has also been speculated by Georges Declercq that Dionysius'
desire to replace
Diocletian years with a calendar based on the
incarnation of Christ was intended to prevent people from believing
the imminent end of the world . At the time, it was believed by some
that the Resurrection and end of the world would occur 500 years after
the birth of Jesus. The old _
Anno Mundi _ calendar theoretically
commenced with the creation of the world based on information in the
Old Testament . It was believed that, based on the _Anno Mundi_
Jesus was born in the year 5500 (or 5500 years after the
world was created) with the year 6000 of the _Anno Mundi_ calendar
marking the end of the world. _Anno Mundi_ 6000 (approximately AD
500) was thus equated with the resurrection and the end of the world
but this date had already passed in the time of Dionysius.
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. In
this same history, he also used another
Latin term, _ante vero
incarnationis dominicae tempus anno sexagesimo_ ("in fact in the 60th
year before the time of the Lord's incarnation"), equivalent to the
English "before Christ", to identify years before the first year of
this era. 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,
Annunciation on March 25" (_
Annunciation style_). _
Agostino Cornacchini (1725), at St. Peter\'s
Basilica , Vatican City.
Charlemagne promoted the usage of the Anno
Domini_ epoch throughout the
On the continent of
Europe , _Anno Domini_ was introduced as the era
of choice of the
Carolingian Renaissance by the English cleric and
Alcuin in the late eighth century. Its endorsement by Emperor
Charlemagne and his successors popularizing the use 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. In
Portugal became the last Western European country to switch to
the system begun by Dionysius.
Eastern Orthodox countries only began
to adopt AD instead of the
Byzantine calendar in 1700 when
so, with others adopting it in the 19th and 20th centuries.
Although _Anno Domini_ was in widespread use by the 9th century, the
term "Before Christ" (or its equivalent) did not become common until
Bede the Venerable used the expression "_anno igitur ante
incarnationem Dominicam_" (so in the year before the Incarnation of
the Lord) twice. "_Anno an xpi nativitate_" (in the year before the
birth of Christ) is found in 1474 in a work by a German monk. In
1627, the French
Denis Pétau (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.
CHANGE OF YEAR
When the reckoning from Jesus' incarnation began replacing the
previous dating systems in western Europe, various people chose
different Christian feast days to begin the year:
Annunciation , or
Easter . Thus, depending on the time and place, the
year number changed on different days in the year, which created
slightly different styles in chronology:
* From 25 March 753 AUC (today in 1 BC), i.e., notionally 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., notionally 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
used in France, England and most of western
Europe (except Spain)
until the 12th century (when it was replaced by
and in Germany until 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 that 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 1752.
* From Easter, starting in 754 AUC (AD 1). That _mos gallicanus_
(French custom) bound to a moveable feast was introduced in France by
king Philip Augustus (1165–1180–1223), maybe to establish a new
style in the provinces reconquered from England. However, it never
spread beyond the ruling élite.
With these various styles, the same day could, in some cases, be
dated in 1099, 1100 or 1101.
HISTORICAL BIRTH DATE OF JESUS
Date of birth of Jesus ,
Nativity of Jesus § Date of birth
Jesus § Historical birth date of
The date of birth of
Jesus of Nazareth is not stated in the gospels
or in any secular text, but most scholars assume a date of birth
between 6 BC and 4 BC. The historical evidence is too sketchy to
allow a definitive dating, but the date is estimated through two
different approaches - one by analyzing references to known historical
events mentioned in the Nativity accounts in the Gospels of Luke and
Matthew, and the second by working backwards from the estimation of
the start of the ministry of
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
(641–668) were appointed consuls on the first
1 January after their
accession. All of these emperors, except Justinian, used imperial
post-consular years for the years of their reign, along with their
regnal years. 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 _
Incarnation_, were exclusively used and are yet used, in
This accounts for the seven- or eight-year discrepancy between the
Gregorian and 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
Eusebius of Caesarea in his _
Chronicle _ used an era beginning with
the birth of
Abraham , dated in 2016 BC (AD 1 = 2017 Anno Abrahami).
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.
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 Orthodox and Coptic Catholic churches.
It was also used by the Ethiopian 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 some medieval manuscripts.
CE AND BCE
Alternative names for the _Anno Domini_ era include _vulgaris aerae_
(found 1615 in Latin), "Vulgar Era" (in English, as early as 1635),
"Christian Era" (in English, in 1652), "
Common Era " (in English,
1708), and "Current Era". Since 1856, the alternative abbreviations
CE and BCE , (sometimes written C.E. and B.C.E.) are sometimes used in
place of AD and BC.
The "Common/Current Era" ("CE") terminology is often preferred by
those who desire a term that does not explicitly make religious
references. 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
Republic of China adopted the
Minguo Era ,
but used the Western calendar for international purposes. The
translated term was 西元 ("xī yuán", "Western Era"). Later, in
1949, the People\'s
Republic of China
Republic of China adopted 公元 (_gōngyuán_,
"Common Era") for all purposes domestic and foreign.
NO YEAR ZERO / START AND END OF A CENTURY
0 (year) ,
Astronomical year numbering , and
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 which has "01" as the final digits (e.g., 1801, 1901,
2001). New millennia likewise are considered to have begun in 1001 and
2001. This is at odds with the much more common conception that
centuries and millennia begin when the trailing digits are zeroes
(1800, 1900, 2000, etc.); for example, the worldwide celebration of
the new millennium took place on New Year's Eve 1999, when the year
number ticked over to 2000.
For computational reasons, astronomical year numbering and the ISO
8601 standard designate years so that AD 1 = year 1, 1 BC = year 0, 2
BC = year −1, etc. In common usage, ancient dates are expressed in
the Julian calendar, but
ISO 8601 uses the
Gregorian calendar and
astronomers may use a variety of time scales depending on the
application. Thus dates using the year 0 or negative years may require
further investigation before being converted to BC or AD.
Ante Christum natum
* ^ The word "anno" is often capitalized, but this is considered
incorrect by many authorities and either not mentioned in major
dictionaries or only listed as an alternative.'s manual of
style also prescribes lowercase.
* ^ 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.
* ^ 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).
* ^ "anno Domini". _Collins English Dictionary_.
* ^ "anno Domini". _
American Heritage Dictionary _. Houghton
Mifflin Harcourt .
* ^ The word "before" is often capitalized, but this is considered
incorrect by many authorities and either not mentioned in major
dictionaries or only listed as an alternative.'s manual of
style also prescribes lowercase.
* ^ "BC". _
Collins English Dictionary _.
* ^ "before Christ". _
American Heritage Dictionary _. Houghton
* ^ "BC". _
Merriam Webster Online Dictionary _.
* ^ "Anno Domini". _Merriam Webster Online Dictionary_.
Merriam-Webster . 2003. Retrieved 2011-10-04. Etymology: Medieval
Latin, in the year of the Lord
* ^ "Online Etymology Dictionary". Retrieved 2011-10-04.
* ^ Blackburn & Holford-Strevens 2003 , p. 782 "since AD stands for
_anno Domini_, 'in the year of (Our) Lord'".
* ^ _A_ _B_ Teresi, Dick (July 1997). "Zero". _
The Atlantic _.
* ^ _A_ _B_ Blackburn & Holford-Strevens 2003 , pp. 778–9.
* ^ Eastman, Allan. "A Month of Sundays". Date and Time. Archived
from the original on 2010-05-06. Retrieved 2010-05-04.
* ^ _Chicago Manual of Style_ 2010, pp. 476–7; Goldstein 2007, p.
* ^ _Chicago Manual of Style,_ 1993, p. 304.
* ^ Donald P. Ryan, (2000), 15.
* ^ Blackburn & Holford-Strevens 2003 , p. 767.
* ^ Nineteen year cycle of Dionysius Introduction and First
* ^ Blackburn & Holford-Strevens 2003 , p. 778.
* ^ Tøndering, Claus, _The
Calendar FAQ: Counting years_
* ^ Mosshammer, Alden A (2009). _The
Easter Computus and the
Origins of the Christian Era_. Oxford. p. 347.
* ^ Declercq, Georges, "Anno Domini. The Origins of the Christian
Era" Turnhout, Belgium, 2000
* ^ Wallraff, Martin: Julius Africanus und die Christliche
Weltchronik. Walter de Gruyter, 2006
* ^ Mosshammer, Alden A.: The
Easter Computus and the Origins of
the Christian Era. Oxford University Press, 2009, p. 254, p. 270, p.
* ^ Declercq, Georges: Anno Domini. The Origins of the Christian
Era. Turnhout Belgium. 2000
Bede 731, Book 1, Chapter 2, first sentence.
* ^ Blackburn & Holford-Strevens 2003 , p. 881.
* ^ _A_ _B_ Patrick, 1908
* ^ "General Chronology". _New Advent Catholic Encyclopedia_. Vol
III. New York:
Robert Appleton Company . 1908. Retrieved 2011-10-25.
Werner Rolevinck in _Fasciculus temporum_ (1474) used _Anno an
xpi nativitatem_ (in the ...(th) year before the birth of Christ) for
all years between creation and
Jesus . "xpi" is the Greek χρι in
Latin letters, which is an abbreviation for _Christi_. This phrase
appears upside down in the centre of recto folios (right hand pages).
Pope Sixtus IV he usually used _Anno Christi_ or its
abbreviated form _Anno xpi_ (on verso folios—left 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 978-0-471-29827-4 . Retrieved
* ^ Hunt, Lynn Avery (2008). _Measuring time, making history_. p.
33. ISBN 978-963-9776-14-2 . Retrieved 2010-06-01.
* ^ Petau, Denis (1758). _search for "ante Christum" in a 1748
reprint of a 1633 abridgement entitled_ Rationarium temporum _by Denis
Petau_. Retrieved 2010-06-01.
C. R. Cheney , _A Handbook of Dates, for students of British
history_, Cambridge University Press, 1945–2000, pp. 8–14.
* ^ Dunn, James DG (2003). "
Jesus Remembered". Eerdmans Publishing:
* ^ Doggett 1992, p579: "Although scholars generally believe that
Christ was born some years before AD 1, the historical evidence is too
sketchy to allow a definitive dating".
Paul L. Maier "The Date of the Nativity and
Jesus" in _Chronos, kairos, Christos: nativity and chronological
studies_ by Jerry Vardaman, Edwin M. Yamauchi 1989 ISBN 0-931464-50-1
* ^ _New Testament History_ by Richard L. Niswonger 1992 ISBN
0-310-31201-9 pp. 121–124
* ^ Roger S. Bagnall and Klaas A. Worp, _Chronological Systems of
Byzantine Egypt_, Leiden, Brill, 2004.
* ^ Alfred von Gutschmid, _Kleine Schriften_, F. Ruehl, Leipzig,
Johannes Kepler (1615). _Joannis Keppleri Eclogae chronicae: ex
epistolis doctissimorum aliquot virorum & suis mutuis, quibus
examinantur tempora nobilissima: 1. Herodis Herodiadumque, 2. baptismi
& ministerii Christi annorum non plus 2 1/4, 3. passionis, mortis et
resurrectionis Dn. N. Iesu Christi, anno aerae nostrae vulgaris 31.
non, ut vulgo 33., 4. belli Iudaici, quo funerata fuit cum Ierosolymis
& Templo Synagoga Iudaica, sublatumque Vetus Testamentum. Inter alia &
commentarius in locum Epiphanii obscurissimum de cyclo veteri
Iudaeorum._ (in Latin). Francofurti : Tampach. Retrieved 2011-05-18.
anno aerae nostrae vulgaris
* ^ Kepler, Johann; Vlacq, Adriaan (1635). _Ephemerides of the
Celestiall Motions, for the Yeers of the Vulgar
Era 1633..._ Retrieved
* ^ Sliter, Robert (1652). _A celestiall glasse, or,
the year of the Christian era 1652 being the bissextile or leap-year:
contayning the lunations, planetary motions, configurations &
ecclipses for this present year ... : with many other things very
delightfull and necessary for most sorts of men: calculated exactly
and composed for ... Rochester_. London: Printed for the Company of
* ^ _The
History of the Works of the Learned_. 10. London: Printed
for H. Rhodes. January 1708. p. 513. Retrieved 2011-05-18.
* ^ BBC Team (8 February 2005). "
History of Judaism
63BCE–1086CE". _BBC Religion & Ethics_. British Broadcasting
Corporation. Archived from the original on 2011-05-13. Retrieved
2011-05-18. Year 1: CE – What is nowadays called the 'Current Era'
traditionally begins with the birth of a Jewish teacher called Jesus.
His followers came to believe he was the promised Messiah and later
split away from Judaism to found Christianity
* ^ Raphall, Morris Jacob (1856). _Post-Biblical
History of The
Jews_. Moss & Brother. Archived from the original on 11 May 2011.
Retrieved 2011-05-18. The term _common era_ does not appear in this
book; the term _Christian era_ does appear a number of times. Nowhere
in the book is the abbreviation explained or expanded directly.
* ^ Robinson, B.A. (20 April 2009). "Justification of the use of
"CE" & "BCE" to identify dates. Trends". ReligiousTolerance.org.
* ^ William Safire (17 August 1997). "On Language: B.C./A.D. or
The New York Times Magazine _.
* ^ Cunningham, ed. by Philip A. (2004). _Pondering the Passion :
what\'s at stake for Christians and Jews?_. Lanham, Md. : Rowman &
Littlefield . p. 193. ISBN 978-0742532182 . CS1 maint: Extra text:
authors list (link )
* ^ Doggett, 1992, p. 579
* Abate, Frank R. (ed.) (1997). _Oxford Pocket Dictionary and
Thesaurus_ (American ed.). New York: Oxford University Press. ISBN
0-19-513097-9 . CS1 maint: Extra text: authors list (link )
* Goldstein, Norm, ed. (2007). _Associated Press Style Book_. New
York: Basic Books. ISBN 0-465-00489-X .
Bede . (731). _Historiam ecclesiasticam gentis Anglorum_. Accessed
* _Chicago Manual of Style_ (2nd ed.). University of Chi