However, as there were not many people who were versed in astronomy in Japan in those days (according to the "Shoku Nihongi" [Chronicle of Japan Continued], paragraph of April 22, 730), careful preparations had to be made (according to the "Shoku Nihongi," paragraph of December 28, 757, concerning which "Ruiju Sandai Kyaku" (Assorted Regulations from Three Reigns) describes that an imperial decree was issued on the same day [December 28]) before it was implemented under the FUJIWARA no Nakamaro government.
だが、当時の日本には暦学に通じた人材が不足していた（『続日本紀』天平2年3月辛亥条）ため、実施には慎重な準備が進められた（『続日本紀』天平宝字元年11月癸未条、『類聚三代格』所収同日（11月9日）勅）後に藤原仲麻呂政権下で実現される事になる。