The terms anno Domini[a] (AD) and before Christ[b] (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 presented using "our Lord" instead
of "the Lord", taken from the full original phrase "anno Domini
nostri Jesu Christi", which translates to "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 525 by
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.[c] However, BC is placed after
the year number (for example: AD 2018, 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 neither be included in the BC nor 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
Astronomical year numbering and ISO
8601 avoid words or abbreviations related to Christianity, but use the
same numbers for AD years.
1.2 Change of year
2 Historical birth date of Jesus
3 Other eras
4 CE and BCE
5 No year zero / Start and end of a century
6 See also
9 External links
Anno Domini dating system was devised in 525 by Dionysius Exiguus
to enumerate the years in his
Easter table. His system was to replace
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". 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."
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
began on 29 August (30 August in the year before a Julian leap year).
There were inaccuracies in the lists 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 example, the
Islamic calendar begins not from the date
of the Hijra, but rather weeks prior, on the first occurrence of the
month of Muharram (corresponding to 16 July 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 calendar,
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
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
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
Agostino Cornacchini (1725), at St. Peter's
Basilica, Vatican City.
Charlemagne promoted the usage of the Anno
Domini epoch throughout the Carolingian Empire.
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
Russia did so, with others adopting it in the 19th and 20th centuries.
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
Denis Pétau (Dionysius Petavius in Latin),
with his work De doctrina temporum, popularized the usage ante
Latin for "Before Christ") to mark years prior to
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: Christmas,
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
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) until the
12th century (when it was replaced by
Annunciation style), 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 (r. 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
See also: Date of birth of Jesus,
Nativity of Jesus
Nativity of Jesus § Date of
Jesus § Historical birth date of Jesus
The date of birth of
Jesus of Nazareth
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 Jesus.
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 Ethiopia. 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 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
Main article: Common Era
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
Further information: 0 (year), Astronomical year numbering,
Millennium, and Century
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, so 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.[d] 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.
^ 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.
^ 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
^ "BC". Collins English Dictionary.
^ "before Christ". American Heritage Dictionary. Houghton Mifflin
^ "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
^ "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. 6.
^ 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 Argumentum.
^ 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.
^ F. A. Shamsi, "The Date of Hijrah", Islamic Studies 23 (1984):
189-224, 289-323 (JSTOR link 1 + JSTOR link 2).
^ 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. 328
^ 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). From
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.
^ 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
Chronology of Jesus" in
Chronos, kairos, Christos: nativity and chronological studies by Jerry
Vardaman, Edwin M. Yamauchi 1989 ISBN 0-931464-50-1 pp. 113–129
^ 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, 1889,
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,
Ephemeris for 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
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
^ 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 [lowercase] does appear a number of
times. Nowhere in the book is the abbreviation explained or expanded
^ 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
B.C.E./C.E.?". The New York Times Magazine.
^ Cunningham, ed. by Philip A. (2004). Pondering the Passion :
what's at stake for Christians and Jews?. Lanham, Md. [u.a.]: 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
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 Chicago. 1993.
Chicago Manual of Style (16th ed.). University of Chicago. 2010.
Blackburn, Bonnie; Holford-Strevens, Leofranc (2003). The Oxford
companion to the Year: An exploration of calendar customs and
time-reckoning. Oxford University Press.
ISBN 0-19-214231-3. Corrected reprinting of original 1999
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): 165–246. 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.
Patrick, J. (1908). "General Chronology". In The Catholic
Encyclopedia. New York: Robert Appleton Company. Retrieved 2008-07-16
from New Advent: http://www.newadvent.org/cathen/03738a.htm
Richards, E. G. (2000). Mapping Time. Oxford: Oxford University Press.
Riggs, John (January 2003). "Whatever happened to B.C. and A.D., and
why?". United Church News. Retrieved 2005-12-19.
Ryan, Donald P. (2000). The Complete Idiot's Guide to Biblical
Mysteries. Alpha Books. p. 15. ISBN 0-02-863831-X.
Look up AD or
Anno Domini in Wiktionary, the free dictionary.
Ab urbe condita
Anno Domini / Common Era
Hindu units of time
Hindu units of time (Yuga)
Canon of Kings
Lists of kings
Pre-Julian / Julian
Old Style and New Style dates
Adoption of the Gregorian calendar
Astronomical year numbering
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ISO week date
Winter count (Plains Indians)
Geological history of Earth
Geological time units
Global Standard Stratigraphic Age (GSSA)
Global Boundary Stratotype Section and Point (GSSP)
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Amino acid racemisation
Terminus post quem