Common Era or Current Era (CE) is one of the notation systems for the world's most widely used calendar era - an alternative to the Dionysian AD and BC system. The era preceding CE is known as before the Common Era or before the Current Era (BCE), while the Dionysian era distinguishes eras as AD (anno Domini, "[the] year of [the] Lord") and BC ("before Christ"). Since the two notation systems are numerically equivalent, "2018 CE" corresponds to "AD 2018" and "400 BCE" corresponds to "400 BC".[a] Both notations refer to the Gregorian calendar (and its predecessor, the Julian calendar). The year-numbering system utilized by the Gregorian calendar is used throughout the world today, and is an international standard for civil calendars.
The expression has been traced back to 1615, when it first appeared in a book by Johannes Kepler as the Latin usage vulgaris aerae, and to 1635 in English as "Vulgar Era".[b] The term "Common Era" can be found in English as early as 1708, and became more widely used in the mid-19th century by Jewish academics. In the later 20th century, the use of CE and BCE was popularized in academic and scientific publications, and more generally by authors and publishers wishing to emphasize secularism or sensitivity to non-Christians, by not explicitly referencing Jesus as "Christ" and Dominus ("Lord") through use of the abbreviation[c] "AD".
The year numbering system used with Common Era notation was devised by the Christian monk Dionysius Exiguus in the year 525 to replace the Era of Martyrs system, because he did not wish to continue the memory of a tyrant who persecuted Christians. He attempted to number years from an initial reference date ("epoch"), an event he referred to as the Incarnation of Jesus. Dionysius labeled the column of the table in which he introduced the new era as "Anni Domini Nostri Jesu Christi".
Numbering years in this manner became more widespread in Europe with its usage by Bede in England in 731. Bede also introduced the practice of dating years before what he supposed was the year of birth of Jesus, and the practice of not using a year zero.[d] In 1422, Portugal became the last Western European country to switch to the system begun by Dionysius.
The term "Common Era" is traced back in English to its appearance as "Vulgar Era"[e] to distinguish dates on the Ecclesiastic calendar from those of the regnal year, the year of reign of a sovereign, typically used in national law.
The first use of the Latin term vulgaris aerae[f] discovered so far was in a 1615 book by Johannes Kepler. Kepler uses it again in a 1616 table of ephemerides, and again in 1617. A 1635 English edition of that book has the title page in English - so far, the earliest-found usage of Vulgar Era in English. A 1701 book edited by John LeClerc includes "Before Christ according to the Vulgar Æra, 6". A 1716 book in English by Dean Humphrey Prideaux says, "before the beginning of the vulgar æra, by which we now compute the years from his incarnation." A 1796 book uses the term "vulgar era of the nativity".
The first so-far-discovered usage of "Christian Era" is as the Latin phrase aerae christianae on the title page of a 1584 theology book. In 1649, the Latin phrase æræ Christianæ appeared in the title of an English almanac. A 1652 ephemeris is the first instance so-far-found for English usage of "Christian Era".
The English phrase "common Era" appears at least as early as 1708, and in a 1715 book on astronomy is used interchangeably with "Christian Era" and "Vulgar Era". A 1759 history book uses common æra in a generic sense, to refer to the common era of the Jews. The first-so-far found usage of the phrase "before the common era" is in a 1770 work that also uses common era and vulgar era as synonyms, in a translation of a book originally written in German. The 1797 edition of the Encyclopædia Britannica uses the terms vulgar era and common era synonymously. In 1835, in his book Living Oracles, Alexander Campbell, wrote: "The vulgar Era, or Anno Domini; the fourth year of Jesus Christ, the first of which was but eight days", and also refers to the common era as a synonym for vulgar era with "the fact that our Lord was born on the 4th year before the vulgar era, called Anno Domini, thus making (for example) the 42d year from his birth to correspond with the 38th of the common era..." The Catholic Encyclopedia (1909) in at least one article reports all three terms (Christian, Vulgar, Common Era) being commonly understood by the early 20th century.
The phrase "common era", in lower case, also appeared in the 19th century in a generic sense, not necessarily to refer to the Christian Era, but to any system of dates in common use throughout a civilization. Thus, "the common era of the Jews", "the common era of the Mahometans", "common era of the world", "the common era of the foundation of Rome". When it did refer to the Christian Era, it was sometimes qualified, e.g., "common era of the Incarnation", "common era of the Nativity", or "common era of the birth of Christ".
An adapted translation of Common Era into pseudo-Latin as Era Vulgaris (in Latin this means Common Mistress) was adopted in the 20th century by some followers of Aleister Crowley, and thus the abbreviation "e.v." or "EV" may sometimes be seen as a replacement for AD.
As early as 1825, the abbreviation VE (for Vulgar Era) was in use among Jews to denote years in the Western calendar.
Common Era notation has also been in use for Hebrew lessons for "more than a century". Some Jewish academics were already using the CE and BCE abbreviations by the mid-19th century, such as in 1856, when Rabbi and historian Morris Jacob Raphall used the abbreviation in his book Post-Biblical History of The Jews.[g]
In the 200 years between 1808 and 2008 the ratio of usage of BCE to BC has increased by about 20% and CE to AD by about 50%, primarily since 1980.
More visible uses of Common Era notation have recently surfaced at major museums in the English-speaking world. Furthermore, several style guides now prefer or mandate its usage. Even some style guides for Christian churches prefer its use: for example, the Episcopal Diocese Maryland Church News.
In the United States, the usage of the BCE/CE notation in textbooks is growing. Some publications have moved over to using it exclusively. For example, the 2007 World Almanac was the first edition to switch over to the BCE/CE usage, ending a 138-year usage of the traditional BC/AD dating notation. It is used by the College Board in its history tests, and by the Norton Anthology of English Literature. Others have taken a different approach. The US-based History Channel uses BCE/CE notation in articles on non-Christian religious topics such as Jerusalem and Judaism.
In June 2006, in the United States, the Kentucky State School Board reversed its decision to use BCE and CE in the state's new Program of Studies, leaving education of students about these concepts a matter of discretion at the local level.
Also in 2011, media reports suggested that the BC/AD notation in Australian school textbooks would be replaced by BCE/CE notation. The story became national news and drew opposition from some politicians and church leaders. Weeks after the story broke, the Australian Curriculum, Assessment and Reporting Authority denied the rumour and stated that the BC/AD notation would remain, with CE and BCE as an optional suggested learning activity.
The use of CE in Jewish scholarship was historically motivated by the desire to avoid the implicit "Our Lord" in the abbreviation AD. Although other aspects of dating systems are based in Christian origins, AD is a direct reference to Jesus as Lord.
Proponents of the Common Era notation assert that the use of BCE/CE shows sensitivity to those who use the same year numbering system as the one that originated with and is currently used by Christians, but who are not themselves Christian.
[T]he Christian calendar no longer belongs exclusively to Christians. People of all faiths have taken to using it simply as a matter of convenience. There is so much interaction between people of different faiths and cultures - different civilizations, if you like - that some shared way of reckoning time is a necessity. And so the Christian Era has become the Common Era.
Adena K. Berkowitz, when arguing at the Supreme Court opted to use BCE and CE because "Given the multicultural society that we live in, the traditional Jewish designations - B.C.E. and C.E. - cast a wider net of inclusion" 
Some oppose the Common Era notation for explicitly religious reasons. Because the BC/AD notation is based on the traditional year of the conception or birth of Jesus, some Christians are offended by the removal of the reference to him in era notation. The Southern Baptist Convention supports retaining the BC/AD abbreviations.
There are also secular concerns. English language expert Kenneth G. Wilson speculated in his style guide that "if we do end by casting aside the AD/BC convention, almost certainly some will argue that we ought to cast aside as well the conventional numbering system [that is, the method of numbering years] itself, given its Christian basis." The short lived French Republican Calendar, for example, began with the first year of the French First Republic and rejected the seven-day week (with its connections to the Book of Genesis) for a ten-day week. Priest and writer on interfaith issues Raimon Panikkar contends that using the designation BCE/CE is a "return... to the most bigoted Christian colonialism" towards non-Christians, who do not necessarily consider the time period following the beginning of the calendar to be a "common era".
According to a Los Angeles Times report, it was a student's use of BCE/CE notation, inspired by its use within Wikipedia, which prompted the teacher and politician Andrew Schlafly to found Conservapedia, a cultural conservative wiki. One of its "Conservapedia Commandments" is that users must always apply BC/AD notation, since its sponsors perceive BCE/CE notation to "deny the historical basis" of the dating system.
The abbreviation BCE, just as with BC, always follows the year number. Unlike AD, which traditionally precedes the year number, CE always follows the year number (if context requires that it be written at all). Thus, the current year is written as 2018 in both notations (or, if further clarity is needed, as 2018 CE, or as AD 2018), and the year that Socrates died is represented as 399 BCE (the same year that is represented by 399 BC in the BC/AD notation). The abbreviations are sometimes written with small capital letters, or with periods (e.g., "B.C.E." or "C.E."). Style guides for academic texts on religion generally prefer BCE/CE to BC/AD.
Etymology: Medieval Latin, in the year of the Lord
anno aerae nostrae vulgaris
The influence of western culture and scholarship upon the rest of the world in turn led to this system of dating becoming the most widely used one across the globe today. Many scholars in historical and religious studies in the West in recent years have sought to lessen the explicitly Christian meaning of this system without abandoning the usefulness of a single, common, global form of dating. For this reason the terms common era and before the common era, abbreviated as CE and BCE, have grown in popularity as designations. The terms are meant, in deference to non-Christians, to soften the explicit theological claims made by the older Latin terminology, while at the same time providing continuity with earlier generations of mostly western Christian historical research.
Herrmann observes, "The changes - showing up at museums, in academic circles and in school textbooks - have been touted as more sensitive to people of faiths outside of Christianity." However, Herrmann notes, "The use of BCE and CE have rankled some Christians"
Part 3 has title: Tomi L Ephemeridvm Ioannis Kepleri pars tertia, complexa annos à M.DC.XXIX. in M.DC.XXXVI. In quibus & tabb. Rudolphi jam perfectis, et sociâ operâ clariss. viri dn. Iacobi Bartschii ... Impressa Sagani Silesiorvm, in typographeio Ducali, svmptibvs avthoris, anno M.DC.XXX.* Translation of title (per 1635 English edition): New Ephemerids for the Celestiall Motions, for the Yeeres of the Vulgar Era 1617-1636
Before Christ according to the Vulgar AEra, 6
reckoning it backward from the vulgar era of Christ's incarnationHumphrey Prideaux, D.D. (1716) [from Oxford University Press 1799 (1716 edition not online, 1749 online is Vol 2)]. The Old and New Testament Connected in the History of the Jews and Neighbouring Nations. 1. Edinburgh. p. 1.
This happened in the seventh year after the building of Rome, and in the second year of the eighth Olympiad, which was the seven hundred forty-seventh year before Christ, i. e. before the beginning of the vulgar æra, by which we now compute the years from his incarnation.
Dionysius the Little brought the vulgar era of the nativity too low by four years.
4 Apr. anno aerae christianae 1584
anni æræ Christianæ, 1649
Some say the World was created 3950 Years before the common Æra of ChristBefore Christ and Christian Era appear on the same page 252, while Vulgar Era appears on page 250
at which time they fixed that for their common eraIn this case, their refers to the Jews.
in the year of the world 3692, and 312 years before the vulgar era.... The Spanish era began with the year of the world 3966, and 38 years before the common era (p63)
St Peter died in the 66th year of the vulgar era
This happened in the 33rd year of the common era, fome time after our Saviour's death.
the common era of the Jews places the creation in BC 3760A. Whitelaw, ed. (1874). Conversations Lexicon. The Popular Encyclopedia. V. Oxford University Press. p. 207.
Hence the present year, 1858, in the common era of the Jews, is AM 5618-5619, a difference of more than 200 years from our commonly-received chronology.Rev. Bourchier Wrey Savile, MA (1858). The first and second Advent: or, The past and the future with reference to the Jew, the Gentile, and the Church of God. London: Wertheim, Macintosh and Hunt. p. 176.
Its epoch is the first of March old style. The common era of the Mahometans, as has already been stated, is that of the flight of Mahomet.Johannes von Gumpach (1856). Practical tables for the reduction of Mahometan dates to the Christian calendar. Oxford University. p. 4.
It should be observed, however, that these years correspond to 492 and 493, a portion of the annals of Ulster being counted from the Incarnation, and being, therefore, one year before the common era of the Nativity of our Lord.James Henthorn Todd (1864). St. Patrick, Apostle of Ireland, A Memoir of his Life and Mission. Dublin: Hodges, Smith & Co, Publishers to the University. pp. 495, 496, 497.
Jews do not generally use the words "A.D." and "B.C." to refer to the years on the Gregorian calendar. "A.D." means "the year of our L-rd," and we do not believe Jesus is the L-rd. Instead, we use the abbreviations C.E. (Common or Christian Era) and B.C.E. (Before the Common Era).
Here is buried his honour Judah ben his honour Joseph, a prince and honoured amongst philanthropists, who executed good deeds, died in his house in the City of Bath, Tuesday, and was buried here on Sunday, 19 Sivan in the year 5585. In memory of Lyon Joseph Esq (merchant of Falmouth, Cornwall). who died at Bath June AM 5585/VE 1825. Beloved and respected.[19 Sivan 5585 AM is June 5, 1825. VE is likely an abbreviation for Vulgar Era.]
For dates, please use the now-standard "BCE-CE" notation, rather than "BC-AD." Authors with strong religious preferences may use "BC-AD," however.
It has been said of the Latin words anno Domini, meaning in the year of our Lord [...]
Marked by the turn of the Common Era, C.E., originally referred to as A.D., an abbreviation of the Latin Anno Domini, meaning "Year of our God/Lord." This was a shortening of Anno Domini Nostri Jesu Christi, meaning "Year of our God/Lord Jesus Christ."
I find this attempt to restructure history offensive," Lori Weintz wrote, in a letter to National Geographic publishers.... The forward to your book says B.C. and A.D. were removed so as to 'not impose the standards of one culture on others.'... It's 2006 this year for anyone on Earth that is participating in day-to-day world commerce and communication. Two thousand six years since what? Most people know, regardless of their belief system, and aren't offended by a historical fact.
This practice [of BCE/CE] is the result of the secularization, anti-supernaturalism, religious pluralism, and political correctness pervasive in our society... retention [of BC/AD] is a reminder to those in this secular age of the importance of Christ's life and mission and emphasizes to all that history is ultimately His Story.
A.D. appears either before or after the number of the year... although conservative use has long preferred before only; B.C. always follows the number of the year.... Common era (C.E.) itself needs a good deal of further justification, in view of its clearly Christian numbering. Most conservatives still prefer A.D. and B.C. Best advice: don't use B.C.E., C.E., or A.C.E. to replace B.C. and A.D. without translating the new terms for the very large number of readers who will not understand them. Note too that if we do end by casting aside the A.D./B.C. convention, almost certainly some will argue that we ought to cast aside as well the conventional numbering system itself, given its Christian basis.
Here is an example of the incarnation's historical-sociological implications among those who feel themselves furthest from Christianity. In certain North American academic circles one can see a return-with repercussions elsewhere-to the most bigoted Christian colonialism, along with the good intention of overcoming it. It has been suggested that the terminology of the Western calendar, Christian in origin, be replaced by one that presumably would be neutral and universal. It is understandable that some would protest the use of A.D. (anno Domini), but by eliminating B.C. (before Christ) and substituting B.C.E. (Before the Common Era) scholars betray the depths of the cultural impact of the historico-Christian event. After all, Jesus was not born in the year 1. We select a single event but without any value judgment. To call our age "the Common Era," even though for the Jews, the Chinese, the Tamil, the Muslims, and many others it is not a common era, constitutes the acme of colonialism.
Certain abbreviations traditionally set in small caps are now in full caps (AD, BCE, and the like), with small caps an option.