olympiad

In ancient Greece, the period of four years between each celebration of the Olympic Games. The method of dating by olympiads was used only for literary and historic purposes and was never adopted in everyday life. The first year of the first olympiad was reckoned to be 776 BC.

Generally, the ancient Greek states each had their own individual dating systems, which could lead to much confustion. Timaeus of Sicily, a Greek historian (c. 356–260 BC), was the first writer who systematically arranged the dates of events by successive olympiads. The practice was followed by the historians Polybius, Diodorus Siculus, Dionysius of Halicarnassus, and others. The last olympiad ended AD 394, when the games were abolished by the emperor Theodosius I the Great.