The postface of this book includes a description of "Zo-shiki-no-toshi" ("the year in which regulations were established"), according to which Konin-shiki (regulations of the Konin era) were established in April 820, the eleventh year of Konin, 14 years after the ruling.
本書の跋に「造式の年」とあり、14年後の嵯峨天皇820年(弘仁11年)4月に『弘仁式』ができている。