His reckonings by Olympiads are generally wrong, the error arising chiefly from carelessness.
They followed the order of the olympiads and archons, and their work was supported by the authority of original documents, monuments and inscriptions.
Boeckh places his life between the 10th and 95th Olympiads (49 6 -39 6 B.C.).
He compiled chronological lists of the archons and Olympiads, and made a collection of Attic inscriptions, the first of its kind in Greece.
Of Hellanicus, the Greek logographer, who appears to have lived through the greater part of the 5th century B.C., and who drew up a chronological list of the priestesses of Here at Argos; of Ephorus, who lived in the 4th century B.C., and is distinguished as the first Greek who attempted the composition of a universal history; and of Timaeus, who in the following century wrote an elaborate history of Sicily, in which he set the example of using the Olympiads as the basis of chronology, the works have perished and our meagre knowledge of their contents is derived only from fragmentary citations in later writers.