An Olympiad is a period of four years associated with the Olympic Games of the Ancient Greeks. During the Hellenistic period, beginning with Ephorus, it was used as a calendar epoch. By this reckoning, the first Olympiad lasted from the summer of 776 BC to that of 772 BC. By extrapolation to the Gregorian calendar, the 4th year of the 698th Olympiad begins in mid-2013.
A modern Olympiad refers to a four-year period beginning January 1 of a year in which the Summer Olympics are due to occur. The first modern Olympiad began in 1896, the second in 1900, and so on (the 30th began in 2012: see the Olympic Charter).
Ancient Olympics 
An Olympiad was a period of four years. Example: Olympiad 140, year 1 = 220/219 BC; year 2 = 219/218 BC; year 3 = 218/217 BC; year 4 = 217/216 BC.
The sophist Hippias was the first writer to publish a list of victors of the Olympic Games, and by the time of Eratosthenes, it was generally agreed that the first Olympic games had happened during the summer of 776 BC. The combination of victor lists and calculations from 776 BC onwards enabled Greek historians to use the Olympiads as a way of reckoning time that did not depend on the time reckonings of one of the city-states. (See Attic calendar.) The first to do so consistently was Timaeus of Tauromenium in the third century BC. Nevertheless, since for events of the early history of the games the reckoning was used in retrospect, some of the dates given by later historian for events before the 5th century BC are very unreliable. In the 2nd century AD, Phlegon of Tralles summarised the events of each Olympiad in a book called Olympiads, and an extract from this has been preserved by the Byzantine writer Photius. Christian chroniclers continued to use this Greek system of dating as a way of synchronising biblical events with Greek and Roman history. In the 3rd century AD, Sextus Julius Africanus compiled a list of Olympic victors up to 217 BC, and this list has been preserved in the Chronicle of Eusebius.
Examples of Ancient Olympiad dates 
- Early historians sometimes used the names of Olympic victors as a method of dating events to a specific year. For instance, Thucydides says in his account of the year 428 BC: "It was the Olympiad in which the Rhodian Dorieus gained his second victory".
- Dionysius of Halicarnassus dates the foundation of Rome to 752 BC: "Romulus, the first ruler of the city, began his reign in the first year of the seventh Olympiad, when Charops at Athens was in the first year of his ten-year term as archon."
- Diodorus Siculus dates the Persian invasion of Greece to 480 BC: "Calliades was archon in Athens, and the Romans made Spurius Cassius and Proculus Verginius Tricostus consuls, and the Eleians celebrated the Seventy-fifth Olympiad, that in which Astylus of Syracuse won the stadion. It was in this year that king Xerxes made his campaign against Greece."
- Jerome, in his Latin translation of the Chronicle of Eusebius, dates the birth of Jesus Christ to year 3 of Olympiad 194, the 42nd year of the reign of the emperor Augustus, which equates to the year 2 BC.
Start of the Olympiad 
An Olympiad started with the games, which were held at the beginning of the Olympic new year, which was on the full moon closest to the summer solstice. (After the introduction of the Metonic cycle about 432 BC, the start of the Olympic year was determined slightly differently).
Though the games were held without interruption, on more than one occasion they were held by others than the Eleiäns. The Eleiäns declared such games Anolympiads (non-Olympics), but it is assumed the winners were nevertheless recorded.
End of the era 
During the 3rd century AD, records of the games are so scanty that historians are not certain whether after 261 they were still held every four years. During the early years of the Olympiad, any physical benefit deriving from a sport was banned. Some winners were recorded though, until the last Olympiad of 393AD. In 394, Roman Emperor Theodosius I outlawed the games at Olympia as pagan. Though it would have been possible to continue the reckoning by just counting four-year periods, by the middle of the 5th century AD reckoning by Olympiads had become disused.
Modern Olympics 
|Olympiad||Start date||End date||Summer Olympics host|
|I||(1st)||1 Jan 1896||31 Dec 1899||Athens, Greece|
|II||(2nd)||1 Jan 1900||31 Dec 1903||Paris, France|
|III||(3rd)||1 Jan 1904||31 Dec 1907||St. Louis, United States|
|IV||(4th)||1 Jan 1908||31 Dec 1911||London, United Kingdom|
|V||(5th)||1 Jan 1912||31 Dec 1915||Stockholm, Sweden|
|VI||(6th)||1 Jan 1916||31 Dec 1919||Not held (Originally Berlin, German Empire)|
|VII||(7th)||1 Jan 1920||31 Dec 1923||Antwerp, Belgium|
|VIII||(8th)||1 Jan 1924||31 Dec 1927||Paris, France|
|IX||(9th)||1 Jan 1928||31 Dec 1931||Amsterdam, Netherlands|
|X||(10th)||1 Jan 1932||31 Dec 1935||Los Angeles, United States|
|XI||(11th)||1 Jan 1936||31 Dec 1939||Berlin, Nazi Germany|
|XII||(12th)||1 Jan 1940||31 Dec 1943||Not held (Originally Tokyo, Japan or Helsinki, Finland)|
|XIII||(13th)||1 Jan 1944||31 Dec 1947||Not held (Originally London, United Kingdom)|
|XIV||(14th)||1 Jan 1948||31 Dec 1951||London, United Kingdom|
|XV||(15th)||1 Jan 1952||31 Dec 1955||Helsinki, Finland|
|XVI||(16th)||1 Jan 1956||31 Dec 1959||Melbourne, Australia|
|XVII||(17th)||1 Jan 1960||31 Dec 1963||Rome, Italy|
|XVIII||(18th)||1 Jan 1964||31 Dec 1967||Tokyo, Japan|
|XIX||(19th)||1 Jan 1968||31 Dec 1971||Mexico City, Mexico|
|XX||(20th)||1 Jan 1972||31 Dec 1975||Munich, West Germany|
|XXI||(21st)||1 Jan 1976||31 Dec 1979||Montreal, Canada|
|XXII||(22nd)||1 Jan 1980||31 Dec 1983||Moscow, Soviet Union|
|XXIII||(23rd)||1 Jan 1984||31 Dec 1987||Los Angeles, United States|
|XXIV||(24th)||1 Jan 1988||31 Dec 1991||Seoul, South Korea|
|XXV||(25th)||1 Jan 1992||31 Dec 1995||Barcelona, Spain|
|XXVI||(26th)||1 Jan 1996||31 Dec 1999||Atlanta, United States|
|XXVII||(27th)||1 Jan 2000||31 Dec 2003||Sydney, Australia|
|XXVIII||(28th)||1 Jan 2004||31 Dec 2007||Athens, Greece|
|XXIX||(29th)||1 Jan 2008||31 Dec 2011||Beijing, China|
|XXX||(30th)||1 Jan 2012||31 Dec 2015||London, United Kingdom|
|XXXI||(31st)||1 Jan 2016||31 Dec 2019||Rio de Janeiro, Brazil|
|XXXII||(32nd)||1 Jan 2020||31 Dec 2023||Istanbul, Turkey; Tokyo, Japan; or Madrid, Spain|
|XXXIII||(33rd)||1 Jan 2024||31 Dec 2027||To be decided|
|XXXIV||(34th)||1 Jan 2028||31 Dec 2031||To be decided|
For the modern Olympics the term was long used to indicate the games themselves, but the IOC now uses it to indicate a period of four years.
Start and end 
The modern Olympiad is a period of four consecutive calendar years, beginning on the first of January of the first year and ending on the thirty-first of December of the fourth year. The Olympiads are numbered consecutively from the first Games of the Olympiad celebrated in Athens in 1896. The XXX Olympiad began on 1 January 2012.
The Summer Olympics are more correctly referred to as the Games of the Olympiad. The first poster to announce the games using this term was the one for the 1932 Summer Olympics, in Los Angeles, using the phrase: Call to the games of the Xth Olympiad
Note, however, that the official numbering of the Winter Olympics does not count Olympiads—- it counts only the Games themselves. For example:
- The first Winter Games, in 1924, were not designated as Winter Games of the VIII Olympiad, but as the I Winter Olympic Games.
- The 1936 Summer Games were the Games of the XI Olympiad. After the 1940 and 1944 Summer Games were canceled due to World War II, the Games resumed in 1948 as the Games of the XIV Olympiad.
- However, the 1936 Winter Games were the IV Winter Olympic Games, and the resumption of the Winter Games in 1948 was designated the V Winter Olympic Games.
Some media people have from time to time referred to a particular (e.g., the nth) Winter Olympics as "the Games of the nth Winter Olympiad", perhaps believing it to be the correct formal name for the Winter Games by analogy with that of the Summer Games. Indeed, at least one IOC-published article has applied this nomenclature as well. This analogy is sometimes extended further by media references to "Summer Olympiads". However, the IOC does not seem to make an official distinction between Olympiads for the summer and winter games, and such usage particularly for the Winter Olympics is not consistent with the numbering discussed above.
The U.S. Olympic Committee often uses the term quadrennium, which it claims refers to the same four-year period. However, it indicates these quadrennia in calendar years, starting with the first year after the Summer Olympics and ending with the year the next Olympics are held. This would suggest a more precise period of four years, but the 2001–2004 Quadrennium would then not be exactly the same period as the XXVIIth Olympiad.
Cultural Olympiad 
|This section requires expansion. (February 2010)|
A Cultural Olympiad is a concept protected by the International Olympic Committee and may be used only within the limits defined by an Organizing Committee for the Olympic Games. From one Games to the next, the scale of the Cultural Olympiad varies considerably, sometimes involving activity over the entire Olympiad and other times emphasizing specific periods within it. Baron Pierre de Coubertin established the principle of ‘Olympic Art Competitions’ at a special congress in Paris in 1906, and the first official programme was presented during the 1912 Games in Stockholm. These competitions were also named the ‘Pentathlon of the Muses’, as their purpose was to bring artists to present their work and compete for ‘art’ medals across five categories: architecture, music, literature, sculpture and painting. Nowadays, while there are no competitions as such, cultural and artistic practice is displayed via the Cultural Olympiad.
The 2012 London Olympics included an extensive Cultural Olympiad with the London 2012 Festival. Cultural events occurred across the British Isles. A major event was the World Shakespeare Festival produced by the RSC and including the Globe to Globe Festival.
At the 2010 Winter Olympics in Vancouver, Cultural Olympiad presented the Cultural Olympiad Digital Edition (or CODE for short). Conforming with the tag-line "Connect.Create.Collaborate.", the festival brought both national and international artists to present digital art, music, and cinema.
Other uses 
The term is still often used popularly to indicate the games themselves, a usage that is strictly erroneous (as an Olympiad is the time period between games) but widely accepted nevertheless. It is also used to indicate international competitions other than physical sports. This includes international science olympiads, such as the International Mathematical Olympiad and the International Linguistics Olympiad and their associated national qualifying tests (e.g., the United States of America Mathematical Olympiad or the North American Computational Linguistics Olympiad), and also events in mind-sports, such as the Science Olympiad, Mindsport Olympiad, Chess Olympiad and Computer Olympiad. In these cases Olympiad is used to indicate a regular event of international competition; it does not necessarily indicate a four-year period.
- Bickerman 1980, p. 75.
- Bickerman 1980, p. 88.
- Photius, Bibliotheca, Terlullian, p. 97.
- Eusebius, Chronicle, Attalus, p. 193.
- Thucydides, 3.8.1 History of the Peloponnesian War, Tufts.
- of Halicarnassus, Dionysius, Roman Antiquities, University of Chicago, 1.75.
- Siculus, Diodorus, Historical Library, University of Chicago, 11.1.2.
- Jerome, Chronological Tables, Attalus, year 2015.
- Olympic Charter - Bye-law to Rule 6
- Team USA: Olympic Games Chronology.
- Kendall, Nigel (2011-04-08). "Community Spirit". International Olympic Committee. Retrieved 2011-06-22. "The XXI Winter Olympiad was to be the first 'social media Games'."
- USOC Quadrennial Congressional Report, June 2009.
- Bickerman, Elias J (1980), Chronology of the Ancient World (Aspects of Greek & Roman Life) (2nd sub ed.), Ithaca, NY: Cornell University Press, ISBN 0-8014-1282-X
- Chris Bennett, The Olympiad System, on tyndalehouse.com
- Valerie Vaughan, The Origin of the Olympics: Ancient Calendars and the Race Against Time (2002) on OneReed.com, an astrologically-oriented site.
- Hellenic Month Established Per Athens,