Because the BC/AD notation is based on the traditional year of the conception or birth of Jesus, removing reference to him in era notation is offensive to some Christians. 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".Ben Johnson of Hampden Academy prefers BC/AD because, among other reasons, the use of identifiers which have common spellings is more ambiguous than the use of identifiers with divergent spellings.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.
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.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.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 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.and the two notations (CE/BCE and AD/BC) are numerically equivalent; thus "2017 CE" corresponds to "AD 2017", and "400 BCE" corresponds to "400 BC".The Gregorian calendar and the year-numbering system associated with it is the calendar system with most widespread use in the world today.
Use of the CE abbreviation was introduced by Jewish academics in the mid-19th century.