There was no single Greek calendar. Almost every Greek community had a calendar of its own, differing from others in the names of the months and the date of the New Year. All were, at least originally, lunar. The months were named after festivals held or deities specially honoured in them. Dios and Artemisios, Macedonian months, were, for example, named after *Zeus and *Artemis; Anthesterion at Athens from the festival *Anthesteria. Such month names are found in Linear B and in literature as early as *Hesiod (Op. 504). In much later times some states used ordinal numbers for their month names.The Athenian calendar is best known. The year began, in theory, with the appearance of the first new moon after the summer solstice, and the months were Hekatombaion, Metageitnion, Boedromion, Pyanopsion, Maimakterion, Posideon, Gamelion, Anthesterion, Elaphebolion, Mounichion, Thargelion, and Skirophorion. All were named after festivals held in the month, some very obscure to us and probably to 5th- and 4th-cent. Athenians. Each month was in length 29 or 30 days; an ordinary year was 354 ± 1, a leap year 384 ± 1 days. A leap year was created by inserting a ‘second’ (δεύτερος) or ‘later’ (ὕστερος) month, usually a second Posideon.