|Time-reckoning in olympiads
The Olympic games took place every four years. The period from the beginning of the games until just before the beginning of the next games was called an ‘olympiad’. By counting these olympiads the Greeks kept track of time over larger periods.
Until the fifth century BC the Greeks had no reliable way of reckoning time. Because they did not count the years from one fixed point in the past, it was difficult to refer to an exact year in the past. In most cities they named each year after an important magistrate of priest. At the end of the fifth century they started composing lists of these magistrates. This inspired Hippias of Elis around 400 BC to compose a list of Olympic victors. Later scholars corrected and updated this list.
Naming a year after an Olympic victor (the man who won the stadion) had a clear advantage over the use of local magistrates: Greeks of different cities recognized the names of these internationally famous champions. Therefore, this way of time-reckoning could spread in the Greek world. The fourth-century philosopher Aristotle made time-reckoning in olympiads easier by numbering the olympiads. Around 300 BC Timaios of Tauromenion examined how the list of Olympic victors corresponded with the lists of local magistrates: he determined for every year which magistrates were in function in Athens and Sparta, who was the priestess of Hera at Argos and in which olympiad it fell. From the third century BC on, many historians used the time-reckoning in olympiads in their writings. Erastosthenes made it even more easy by numbering the four years of each olympiad. What in our time-reckoning is 776 BC, was for the Greeks the first year of the first olympiad, in which Koroibos of Elis won the stadion.
The time-reckoning in olympiads continued into the Byzantine period, that is after the games themselves had disappeared. The church-historian Eusebius left us one olympic chronicle (a chronological list of stadion victors with historical facts added) until 217 AD. In late antiquity historians no longer used the names of the victors of the stadion, but only the numbers of the olympiads.