Prytaneis

...The length of night was usually determined based on the interval between shifts of the military guard; Homer had three shifts, but after the Classical period, the Egyptian custom of four shifts was adopted, and each shift (phyrake) was named with an ordinal number. The calendar year was represented by the name of the head of the archon (who had a one-year term of office) and by the period of duty of the Prytaneis, who were the executive committee of the Athenian assembly. The Prytaneis were a committee of 15 people chosen by lot from each of the 10 Athenian tribes, and their period of duty was therefore between 34 and 39 days.

*Some of the terminology explanations that mention "Prytaneis" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…なお夜の時間は，軍隊の見張りの交替までの間隔を基準にして定めるのがふつうで，ホメロスでは3交替，古典期以降はエジプトの習慣をとり入れ4交替となり，それぞれの間隔(フュラケ)を序数詞で名付けた。　暦年は，アルコン(任期1年)のうち筆頭者の名を冠して表す方法と民会の執行委員会ともいうべきプリュタネイスPrytaneisの当番期間によって表す方法が用いられた。プリュタネイスはアテナイの10の部族からくじで選ばれる各15人の委員で，したがってその当番期間は34日から39日の間となっていた。…

※「Prytaneis」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報