History of the Peloponnesian War

10. If anything be forgotten, whatever it be, and on whatever point, it shall be consistent with their oath for both parties the Athenians and Lacedaemonians to alter it, according to their discretion.

The treaty begins from the Ephoralty of Pleistolas in Lacedaemon, on the 27th day of the month of Artemisium, and from the Archonship of Alcaeus at Athens, on the 25th day of the month of Elaphebolion.

Those who took the oath and poured the libations for the Lacedaemonians were Pleistoanax, Agis, Pleistolas, Damagetus, Chionis, Metagenes, Acanthus, Daithus, Ischagoras, Philocharidas, Zeuxidas, Antippus, Tellis, Alcinadas, Empedias, Menas, and Laphilus; for the Athenians, Lampon, Isthmionicus, Nicias, Laches, Euthydemus, Procles, Pythodorus, Hagnon, Myrtilus, Thrasycles, Theagenes, Aristocrates, Iolcius, Timocrates, Leon, Lamachus and Demosthenes.

This treaty was made in the spring, just at the end of winter, directly after the city festival of Dionysus, just ten years, with the difference of a few days, from the first invasion of Attica and the commencement of this war.

This must be calculated by the seasons rather than by trusting to the enumeration of the names of the several magistrates or offices of honor that are used to mark past events. Accuracy is impossible where an event may have occurred in the beginning, or middle, or at any period in their tenure of office.

But by computing by summers and winters, the method adopted in this history, it will be found that, each of these amounting to half a year, there were ten summers and as many winters contained in this first war.