There is no year zero in the widely used Gregorian calendar, nor in its predecessor, the Julian calendar. The Gregorian calendar is the most widely used Calendar in the world today The Julian calendar, a reform of the Roman calendar, was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 Ab urbe condita Under those systems, the year 1 BC is followed by AD 1. However, there is a year zero in astronomical year numbering (where it coincides with the Julian year 1 BC) and in ISO 8601:2004 (where it coincides with the Gregorian year 1 BC) as well as in all Buddhist and Hindu calendars. Astronomical year numbering is based on AD ( Anno Domini)/CE ( Common Era) year numbering but follows normal Decimal Integer numbering more strictly ISO 8601 is an International standard for date and Time representations issued by the International Organization for Standardization (ISO The Buddhist calendar is used on mainland Southeast Asia in the countries of Cambodia, Laos, Thailand, Myanmar (formerly Burma The Hindu calendar used in ancient times has undergone many changes in the process of regionalization and today there are several regional Indian Calendars, as

Historians

Further information: Anno Domini and Dionysius Exiguus

Dionysius Exiguus (c. Dionysius Exiguus ( Dennis the Little or Dennis the Short, meaning humble (c 470–c. Events By Place Europe Euric, king of the Visigoths, defeats an attempted invasion of Gaul by the Celtic 544) introduced the anno Domini era, which he used to identify the several Easters in his Easter table, but did not use it to date any historical event. Events By Place Byzantine Empire Belisarius is sent back to Italy to once more fight the Ostrogoths who have An era is a commonly used word for long period of time When used in science for example geology eras denote clearly defined periods of time of arbitrary but well defined Dionysius Exiguus' Easter table was constructed in the year 525 by Dionysius Exiguus for the years 532–626 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 [Flavius Probus]", which he also stated was 525 years "since the incarnation of our Lord Jesus Christ". Consul (abbrev cos; Latin plural consules) was the highest elected office of the Roman Republic and an appointive office under the Empire ^[1] How he arrived at that number is unknown. He invented a new system of numbering years to replace the Diocletian years that had been used in an old Easter table because he did not wish to continue the memory of a tyrant who persecuted Christians. Gaius Aurelius Valerius Diocletianus ( ca. December 22 244 The modern historian Timothy Barnes takes December 22 as his birthdate

Bede (c. Bede (ˈbiːd (also Saint Bede, the Venerable Bede, or (from Latin Beda (beda (c 672–735) was the first historian to use a BC year, and hence the first one to choose 1 as the origin of the BC era, thus 1 BC, in his Historia ecclesiastica gentis Anglorum (Ecclesiastical history of the English people, 731). The Historia ecclesiastica gentis Anglorum (in English: Ecclesiastical History of the English People) is a work in Latin by the Bede did not sequentially number days of the month, weeks of the year, or months of the year, but he did number many of the days of the week using a counting origin of one in Ecclesiastical Latin. The Roman calendar changed its form several times in the time between the foundation of Rome and the fall of the Roman Empire. The names of the days of the week in various world languages can be classified as either numerical or planetary; however in either case the names of one or more days Ecclesiastical Latin (sometimes called Church Latin) is the Latin dialect as used in documents of the Roman Catholic Church and in its Latin liturgies Previous Christian histories used anno mundi ("in the year of the world") beginning on the first day of Creation, or anno Adami ("in the year of Adam") beginning at the creation of Adam five days later (the sixth day of Creation week), used by Africanus, or anno Abrahami ("in the year of Abraham") beginning 3,412 years after Creation according to the Septuagint, used by Eusebius, all of which assigned "one" to the year beginning at Creation, or the creation of Adam, or the birth of Abraham, respectively. la Anno Mundi (Latin "in the year of the World " abbreviated as AM or A Cultures throughout history have believed the world formed or was formed at some time in the past so methods of dating Creation have involved analysing scriptures and some physical See also Adam and Eve Adam ( Hebrew: אָדָם was according to a literal interpretation of Genesis, the first man created by Creation according to Genesis refers to the Hebrew narrative of the creation of the heavens and the earth as told in chapters 1 and 2 of Genesis Abraham ( Ashkenazi   Avrohom or Avruhom; ابراهيم, {{Unicode|Ibrāhīm}}; Ge'ez: The Septuagint (ˈsɛptuədʒɪnt or simply " LXX " is the Koine Greek version of the Hebrew Bible, translated in stages between the Bede continued this earlier tradition relative to the AD era.

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 fortysixth [year] from the incarnation of our Lord". Rome ( Roma ˈroma Roma is the capital city of Italy and Lazio, and is Italy's largest and most populous city with more than 2 Tiberius Claudius Caesar Augustus Germanicus or Claudius I ( August 1, 10 BC &ndash October 13, AD 54 ( Tiberius Claudius Drusus from birth to ^[2] 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 (albeit with a correct year).

It is often stated that Bede did not use a year zero because he did not know about the number zero. Although the Arabic numeral for zero (0) did not enter Europe until the eleventh century, and Roman numerals had no symbol for zero, Bede and Dionysius Exiguus did use a Latin word, nulla meaning "nothing", alongside Roman numerals or Latin number words wherever a modern zero would have been used. The arabic numerals (often capitalized are the ten Digits (0 1 2 3 4 5 6 7 8 9 which—along with the system Roman numerals are a Numeral system originating in ancient Rome, adapted from Etruscan numerals. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. ^[1][3][4]

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). Werner Rolevinck (1425-1502 was a Carthusian Monk and historian who wrote about 50 titles ^[5] 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. Western Europe at its most general meaning means 'all the countries in the West of Europe ' New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC Events 406 – Vandals, Alans and Suebians cross the Rhine, beginning an invasion of Gallia. 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. The Renaissance (from French Renaissance, meaning "rebirth" Italian: Rinascimento, from re- "again" and nascere Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. But vulgar era was suppressed 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". English is a West Germanic language originating in England and is the First language for most people in the United Kingdom, the United States Consequently, historians regard all these eras as equal.

Since Bede, historians have not counted with a year zero. This means that between, for example, January 1, 500 BC and January 1, AD 500, there are 999 years: 500 for BC years, and 499 for AD years preceding 500. New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC Events By Place Europe Possible date for the Battle of Mons Badonicus: Romano-British and Celts defeat an Anglo-Saxon In common usage anno Domini 1 is preceded by the year 1 BC, without an intervening year zero. Ante Christum (Natum is also an album by the band Shadows Land Ante Christum Natum ante Christi natum -->( Latin for ^[6] Thus the year 2006 actually signifies "the 2006th year". Neither the choice of calendar system (whether Julian or Gregorian) nor the era (Anno Domini or Common Era) determines whether a year zero will be used. The Julian calendar, a reform of the Roman calendar, was introduced by Julius Caesar in 46 BC and came into force in 45 BC (709 Ab urbe condita The Gregorian calendar is the most widely used Calendar in the world today 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. No historian includes a year 0 when numbering years in the current standard era. Historians even refuse to use a year 0 when using negative years before our positive era, hence their −1 immediately precedes 1. ^[7]

Numerical explanation

There are two different ways of recording time:

• One is to use cardinal numbers (e. g. one, two, three, . . . ) or ordinal numbers (e. g. first, second, third, . . . ) This corresponds to treating time as a discrete variable, and the labels as counts. A variable (ˈvɛərɪəbl is an Attribute of a physical or an abstract System which may change its Value while it is under Observation. Counting is the mathematical action of repeatedly adding (or subtracting one usually to find out how many objects there are or to set aside a desired number of objects (starting Under this point of view, the first year counted after the starting point will come immediately after the first year counted before the starting point. Thus AD 1 comes immediately after 1 BC.
• In some contexts, however, such as astronomy, it can be more convenient to regard time as a continuous variable, and label time periods as intervals on a continuous scale, that is, as measurements of the total time elapsed since the start of the era. Astronomy (from the Greek words astron (ἄστρον "star" and nomos (νόμος "law" is the scientific study With regards to Time, an interval or period is the Duration between two events or occurrences of similar events An era is a commonly used word for long period of time When used in science for example geology eras denote clearly defined periods of time of arbitrary but well defined According to this interpretation, elapsed time year 1 begins exactly one full year after the starting point, and the first year is year 0 (meaning that zero full years have elapsed since the starting point).

The first way of reckoning described above is the traditional one in historiography and in common usage to label years, centuries, and millennia. The second is used, for example, with a person's age.

A similar distinction occurs in numbering the floors of a building, and the exits of a highway. A storey (spelled story in the USA only floor, deck or level is the level of a Building above (or below the Ground. There are several places with a Highway interchange labeled as Exit 0 ( zero)

Third millennium

The third millennium of the Gregorian calendar began on 1 January 2001 (rather than the popularly-celebrated 1 January 2000). New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC Year 2001 ( MMI) was a Common year starting on Monday according to the Gregorian calendar. New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC 2000 ( MM) was a Leap year that started on Saturday of the Common Era, in accordance with the Gregorian calendar. This is a direct consequence of the absence of a year zero in the anno Domini era. Had there been a year zero, which might be considered part of the first millennium, then 1 January 2000 would indeed mark 2000 years since the year numbering datum and be the start of the third millennium. New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC 2000 ( MM) was a Leap year that started on Saturday of the Common Era, in accordance with the Gregorian calendar.

Note that this also applies to centuries. Thus, the 20th century actually began on 1 January 1901. New Year See also New Year The Ancient Romans began their consular year on January 1st since 153 BC Year 1901 ( MCMI) was a Common year starting on Tuesday (link will display calendar of the Gregorian calendar (or a Common year starting

Astronomical year numbering

Astronomers

Astronomers, for whom ease of mathematical calculation is more important, have used a defined leap year zero equal to 1 BC of the traditional Christian era since the 18th century. Historically Astronomy was more concerned with the classification and description of phenomena in the sky while Astrophysics attempted to explain these phenomena The first use of an astronomical year 0 is traditionally attributed to Jacques Cassini whose stated reasons for including a year zero were:

The year 0 is that in which one supposes that Jesus Christ was born, which several chronologists mark 1 before the birth of Jesus Christ and which we marked 0, so that the sum of the years before and after Jesus Christ gives the interval which is between these years, and where numbers divisible by 4 mark the leap years as so many before or after Jesus Christ. Jacques Cassini ( February 8, 1677 – April 18, 1756) was a French - Italian Astronomer, son of the famous Italian

—Jacques Cassini, Tables astronomiques (Astronomical Tables), 1740, p. 5, translated from French

But Philippe de La Hire had used a year zero earlier in 1702 in his Tabulæ Astronomicæ (Astronomical Tables) in the form Christum o. Philippe de La Hire (or Lahire or Phillipe de La Hire) ( March 18, 1640 — April 21, 1718) was a French ("Christ 0"), without explanation. Both Cassini and La Hire used BC years before their year 0 and AD years thereafter (hence the sequence 1 BC, 0, AD 1). That is why Cassini stated that their sum yielded the interval. For example, 1 + 1 = 2. Beginning in the 19th century, some astronomers began to use negative years before their year 0, while other astronomers continued to use BC years before their year 0. By the mid 20th century, all astronomers were using negative years before year 0 (hence the sequence −1, 0, 1). Thus modern astronomers would state that the years' difference yields the interval, just as it does if the years are both positive or both negative. For example, 1 − (−1) = 2, and 2000 − 1999 = 1. Although 'AD' is omitted from later years, leaving a bare number, a positive sign (+) is sometimes prefixed to the number. Because of possible confusion with the earlier use of an astronomical BC, only in the modern version can it be said that astronomical year 0 equals the historical year 1 BC.

ISO 8601

ISO 8601:2004 (and previously ISO 8601:2000, but not ISO 8601:1988) explicitly uses astronomical year numbering in its date reference systems. ISO 8601 is an International standard for date and Time representations issued by the International Organization for Standardization (ISO Because it also specifies the use of the proleptic Gregorian calendar for all years before 1582, some readers incorrectly assume that a year zero is also included in that proleptic calendar, whereas that is unusual. The proleptic Gregorian calendar is produced by extending the Gregorian calendar backward to dates preceding its official introduction in 1582. The "basic" format for year 0 is the four-digit form 0000, which equals the historical year 1 BC. Several "expanded" formats are possible: -0000 and +0000, as well as five- and six-digit versions. Earlier years are also negative four-, five- or six-digit years, which have an absolute value one less than the equivalent BC year, hence -0001 = 2 BC. In Mathematics, the absolute value (or modulus) of a Real number is its numerical value without regard to its sign. Because only ISO 646 (7-bit ASCII) characters are allowed by ISO 8601, the minus sign is represented by a hyphen-minus. ISO 646 is an ISO standard that since 1972 has specified a 7- Bit character code from which several national standards are derived American Standard Code for Information Interchange ( ASCII) The hyphen-minus is the character at position 2D HEX in ASCII and standards that derive from it

Other traditions

South Asian calendars

All eras used with Hindu and Buddhist calendars, such as the Saka era or the Kali Yuga, begin with the year 0. The Hindu calendar used in ancient times has undergone many changes in the process of regionalization and today there are several regional Indian Calendars, as The Buddhist calendar is used on mainland Southeast Asia in the countries of Cambodia, Laos, Thailand, Myanmar (formerly Burma The Shalivahana era, also known as the Saka era, is used with Hindu calendars the Indian national calendar, and the Cambodian Buddhist calendar Kali Yuga ( Devanāgarī: sa कलियुग lit "Age of Kali " "age of vice" is one of the four stages of development that the world goes All these calendars use elapsed, expired, or complete years, in contrast with most other calendars 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, xx minutes. Description A time of day is written in the 24-hour notation in the form hhmm (for example 0123 or hhmmss (for example 012345 where hh (00 to 23 is the decimal number

Maya historiography

Many Maya historians, but not all, assume (or used to assume) that a year 0 exists in the modern calendar and thus specify that the epoch of the Mesoamerican Long Count calendar occurred in 3113 BC rather than 3114 BC. The Maya civilization is a Mesoamerican Civilization, noted for the only known fully developed written language of the Pre-Columbian Americas This would require the sequence 1 BC, 0, AD 1 as in early astronomical years.

Popular culture

• In the movie Back to the Future, Dr. Emmett Brown, the inventor of a time machine, enters the input date of the "birth of Christ" on a keypad as December 25, 0000, implying that he uses the astronomical year numbering. Back to the Future is a 1985 science fiction Comedy film directed by Robert Zemeckis and produced by Steven Spielberg. "Doc Brown" redirects here For the British rapper see Doc Brown (rapper. Jesus of Nazareth (7–2 BC / BCE —26–36 AD / CE) It should be noted that the DVD commentary clearly points out that the date was a joke.
• In the movie, The Beach, Leonardo DiCaprio's character is, during his mental instability, crazed about the term Year 0. The Beach is a 2000 Drama film by the Trainspotting team of writer John Hodge, producer Andrew Macdonald and
• The fictitious theologian Franz Bibfeldt's most famous work relates to the year 0: a 1927 dissertation submission to the University of Worms entitled "The Problem of the Year 0". Franz Bibfeldt is a famous fictitious theologian and in-joke among American academic theologians
• The Zork timeline included with the comedy game Zork Grand Inquisitor features the year 0 GUE with the annotation: "As the year zero begins, people feel fairly confident that something big is about to happen. Zork was one of the first Interactive fiction Computer games and an early descendant of Colossal Cave Adventure. "
• Panic in Year Zero! is a 1962 science fiction film directed by and starring Ray Milland. Panic in Year Zero!, sometimes known as End of the World, is a 1962 Science fiction film directed by and starring Ray Milland The year 1962 in film involved some significant events Events Dr Science fiction Film is a Film genre that uses speculative, Science -based depictions of imaginary phenomena such as extra-terrestrial Ray Milland ( January 3, 1907 - March 10, 1986) was a Welsh Actor and director who worked primarily in the 1962 becomes the year zero when Los Angeles is destroyed by a hydrogen bomb as part of a worldwide nuclear war. Los Angeles (lɑˈsændʒələs los ˈaŋxeles in Spanish) is the largest City in the state of California and the American West The Teller–Ulam design is a Nuclear weapon design which is used in Megaton -range Thermonuclear weapons and is more colloquially referred to as "the

References