An article on calendar making given in the Zoryo (Law on Miscellaneous Matters) of the Yoro Ritsuryo Code stipulate that Onmyoryo (more concretely Rekihakase) should make beforehand a New Year calendar and submit it to the Nakatsukasasho on every November 1st and that the Nakatsukasasho should present it to the Emperor.
養老律令雑令造暦条に、陰陽寮（具体的には暦博士）が毎年予め来年の暦を作成して11月1日に中務省に送り、同省はそれを天皇に奏聞すること。