Abstract
In 424B.C., Aristophanes, a most famous comic poet, had his chorus appeal that Selene complained the calendar did not observe the moon to the Athenian citizens in Clouds. Many students of the calendar or astronomy, especially B.D.Meritt and W.K.Pritchett, have argued over his jest and the calendar of the last quarter of the fifth century Athens. But we have had no persuasive opinion so far. This article is to reexamine historical inscriptions and literal sources that the scholars have examined.
Athenians had two calendars in those days. One was a calendar of the prytanies (the Standing Committee) which was divided into ten ‘months’, the other was a lunar calendar which we can call a festival calendar. These two calendars began and ended their years separately. All the scholars have thought that either of these calendars had its regularity, and that the complaints of the moon was caused by the irregularity of the other calendar. But I found the regularities of these two calendars reexamining the inscriptions of IG i3 369 or i3 377. But this regularity did not continue through the last fifth century. It was revised one time around 419/8 B.C. After this revision, the new system had its regularity, and this has long puzzled scholars.
