CenturyLook up century in
Wiktionary, the free dictionary. For other uses, see Century (disambiguation). "Centennial" redirects here. For other uses, see Centennial (disambiguation). "Centenary" redirects here. For other uses, see Centenary (disambiguation).
- 1 Start and End in the Gregorian Calendar
- 2 Dating Systems before the Century
- 3 Centuries in Astronomical Year Numbering
- 4 References
- 5 See also
Start and End in the Gregorian Calendar
According to the Gregorian calendar, the 1st century AD started on January 1, 1 and ended on December 31, 100. The 2nd century started at year 101, the third at 201, etc. The n-th century will start on the year 100×n - 99. A century will only include one year, the centennial year, that starts with the century's number (e.g. 1900 is in the 19th century).
End of the 20th century
1st Century AD and BC
Dating Systems before the Century
The oldest dating systems were based on the reigns of monarchs, (e.g. the fifteenth year of King George). Similarly, other systems arose dating from the founding of a dynasty, city or religion. For example, Ab urbe condita counts the Year 1 as the founding of Rome, Anno Domini as the first full year of Jesus Christ's life and the Islamic calendar counts in the year of the Hijra. The Gregorian calendar adopted Anno Domini as the basis for its numbering system.
Centuries in Astronomical Year Numbering
Astronomical year numbering, used by astronomers) includes a year zero. Consequently, the first century in these calendars may designate the years 0 to 99 as the first century. and to regard 2000 as the first year of the twenty-first century, the year 0 corresponding then to Georgian year 1 BC.
"The Battle of the Centuries", Ruth Freitag, U.S. Government Printing Office. Available from the Superintendent of Documents, P.O. Box 371954, Pittsburgh, PA 15250- 7954. Cite stock no. 030-001-00153-9.
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