Year zero

Source: Wikipedia, the free encyclopedia.
For other uses, see Year zero (disambiguation). "0 A.D." redirects here. For the video game, see 0 A.D. (video game).

A year zero does not exist in the

conversion table). There is also a year zero in most Buddhist and Hindu calendars
.

History

The

Jesus Christ".[1] How he arrived at that number is unknown.[2]

Dionysius Exiguus did not use 'AD' years to date any historical event. This practice began with the English cleric

Historia ecclesiastica gentis Anglorum (731), popularizing the era. Bede also used - only once - a term similar to the modern English term 'before Christ', though the practice did not catch on for nearly a thousand years, when books by Dionysius Petavius treating calendar science gained popularity. Bede did not sequentially number days of the month, weeks of the year, or months of the year. However, he did number many of the days of the week using the counting origin one in Ecclesiastical Latin.[citation needed
]

Previous Christian histories used several titles for dating events:

Eusebius of Caesarea; all of which assigned "one" to the year beginning at Creation, or the creation of Adam, or the birth of Abraham, respectively. Bede continued this earlier tradition relative to the AD era.[citation needed
]

In chapter II of book I of Ecclesiastical History, Bede stated that Julius Caesar invaded Britain "in the year 693 after the building of Rome, but the sixtieth year before the incarnation of our Lord", while stating in chapter III, "in the year of Rome 798, Claudius" also invaded Britain and "within a very few days ... concluded the war in ... the forty-sixth [year] from the incarnation of our Lord".[3] Although both dates are wrong, they are sufficient to conclude that Bede did not include a year zero between BC and AD: 798 − 693 + 1 (because the years are inclusive) = 106, but 60 + 46 = 106, which leaves no room for a year zero. The modern English term "before Christ" (BC) is only a rough equivalent, not a direct translation, of Bede's Latin phrase ante incarnationis dominicae tempus ("before the time of the lord's incarnation"), which was itself never abbreviated. Bede's singular use of 'BC' continued to be used sporadically throughout the Middle Ages.[citation needed]

Neither the concept of nor a symbol for zero existed in the system of

0) did not enter Europe until the thirteenth century. Even then, it was known only to very few, and only entered widespread use in Europe by the seventeenth century.[citation needed
]

The anno Domini nomenclature was not widely used in Western Europe until the 9th century, and the 1 January to 31 December historical year was not uniform throughout Western Europe until 1752. The first extensive use (hundreds of times) of 'BC' occurred in Fasciculus Temporum by Werner Rolevinck in 1474, alongside years of the world (anno mundi).[6] The terms anno Domini, Dionysian era, Christian era, vulgar era, and common era were used interchangeably between the Renaissance and the 19th century, at least in Latin. But vulgar era fell out of use in English at the beginning of the 20th century after vulgar acquired the meaning of "offensively coarse", replacing its original meaning of "common" or "ordinary". Consequently, historians regard all these eras as equal.[citation needed]

Historians have never included a year zero. This means that between, for example, 1 January 500 BC and 1 January AD 500, there are 999 years: 500 years BC, and 499 years AD preceding 500. In common usage anno Domini 1 is preceded by the year 1

BC, without an intervening year zero.[7] Neither the choice of calendar system (whether Julian or Gregorian) nor the name of the era (Anno Domini or Common Era) determines whether a year zero will be used. If writers do not use the convention of their group (historians or astronomers), they must explicitly state whether they include a year 0 in their count of years, otherwise their historical dates will be misunderstood.[8]

Astronomy

Main article: Astronomical year numbering

In astronomy, for the year AD 1 and later it is common to assign the same numbers as the Anno Domini notation, which in turn is numerically equivalent to the Common Era notation. But the discontinuity between 1 AD and 1 BC makes it cumbersome to compare ancient and modern dates. So the year before 1 AD is designated 0, the year before 0 is −1, and so on.

The letters "AD", "BC", "CE", or "BCE" are omitted. So 1 BC in historical notation is equivalent to 0 in astronomical notation, 2 BC is equivalent to −1, etc. Sometimes positive years are preceded by the + sign. This year numbering notation was introduced by the astronomer Jacques Cassini in 1740.[9]

History of astronomical usage

In 1627, the German astronomer

Philippe de la Hire labeled a year as Christum 0 and placed it at the end of the years labeled ante Christum (BC), and immediately before the years labeled post Christum (AD), on the mean motion pages in his Tabulæ Astronomicæ, thus adding the number designation 0 to Kepler's Christi.[11]

Finally, in 1740, the transition was completed by French astronomer Jacques Cassini (Cassini II), who is traditionally credited with inventing year zero.[12] In his Tables astronomiques, Cassini labeled the year simply as 0, and placed it at the end of years labeled avant Jesus-Christ (BC), and immediately before years labeled après Jesus-Christ (AD).[13]

ISO 8601

ISO 646 (7-bit ASCII) characters are allowed by ISO 8601, the minus sign is represented by a hyphen-minus
.

Computing

Programming libraries may implement a year zero, an example being the Perl CPAN module DateTime.[14]

Indian calendars

Most eras used with

Saka era or the Kali Yuga, begin with the year 0. These calendars mostly use elapsed, expired, or complete years, in contrast with most calendars from other parts of the world which use current years. A complete year had not yet elapsed for any date in the initial year of the epoch, thus the number 1 cannot be used. Instead, during the first year the indication of 0 years (elapsed) is given in order to show that the epoch is less than 1 year old. This is similar to the Western method of stating a person's age – people do not reach age one until one year has elapsed since birth (but their age during the year beginning at birth is specified in months or fractional years, not as age zero). However, if ages were specified in years and months, such a person would be said to be, for example, 0 years and 6 months or 0.5 years old. This is analogous to the way time is shown on a 24-hour clock
: during the first hour of a day, the time elapsed is 0 hours, n minutes.

See also

  • January 0

References

  1. ^ a b "Dionysius Exiguus. Liber de paschate sive cyclus paschalis". Archived from the original on 9 January 2006.
  2. ISBN 9780192142313
    .
  3. ^ "Ecclesiastical History of the English Nation". Archived from the original on 30 August 2009. Retrieved 5 August 2005.
  4. ISBN 0-85323-693-3
    .
  5. ISBN 978-0-19-722416-8
    .
  6. ^ Werner Rolevinck, Fasciculus temporum Archived 10 February 2016 at the Wayback Machine.
  7. ^ While it is increasingly common to place AD after a date by analogy to the use of BC, formal English usage adheres to the traditional practice of placing the abbreviation before the year as in Latin (e.g., 100 BC, but AD 100).
  8. ^ V. Grumel, La chronologie (1958), page 30.
  9. ISBN 978-1-891389-85-6
    .
  10. ^ "Tabulae Rudolphinae – Ioannes Keplerus" Archived 11 May 2017 at the Wayback Machine (1627) 191 (42), 197 (48), 203 (54), 209 (60), 215 (66), 221 (72), 227 (78).
  11. ^ Tabulae Astronomicae – Philippo de la Hire Archived 26 March 2023 at the Wayback Machine (1702), Tabulæ 15, 21, 39, 47, 55, 63, 71; Usus tabularum 4.
  12. ^ Robert Kaplan, The nothing that is Archived 30 June 2023 at the Wayback Machine (Oxford: Oxford University Press, 2000) 103.
  13. ^ [Jacques] Cassini, Tables astronomiques (1740), Explication et usage 5; Tables 10, 22, 53.
  14. ^ "DateTime – A date and time object – metacpan.org". Archived from the original on 5 March 2020. Retrieved 2 April 2019.
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