Engikyaku, a collection of amendments to and enforcement regulations for Ritsuryo (basic national laws), was completed in November 907 (old calendar) during the Heian period and put into force by a senji (written order of the Emperor) in December of the following year (old calendar).
延喜格（えんぎきゃく）は、平安時代の延喜7年（907年）11月_(旧暦)に完成し、翌年12月の宣旨によって施行された格式。