"Kansei Calendar"

…After the death of his father, Shigetoki, who almost singlehandedly accomplished the Kansei calendar reform, he did not have the ability to understand other astronomy officials, so he did not write a detailed description of the Kansei calendar. In 1804, 40 years after its implementation, the shogunate ordered Keisuke to oversee its revision. Keisuke played a central role in writing and presented the 35 volumes of the Kansei Calendar and the 5 volumes of the Kansei Calendar Continued. Keisuke wrote at the beginning of the volume, "Those who study calendars are not clear about mathematics and are not skilled in measurement, and there is no one who can achieve anything." He left behind many unparalleled writings. …

*Some of the terminology explanations that refer to the Kansei Calendar are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…寛政改暦をほとんど独力で成し遂げた父至時の死後は他の天文方に理解する能力がなかったため，寛政暦法の詳しい暦理の撰述（せんじゆつ）は進（しんちよく）せず，その施行後40年も経た39年幕府は景佑に命じて督修させた。44年，景佑が中心となって《寛政暦書》35巻，《寛政暦書続録》5巻が撰述され上呈された。この巻頭に〈暦学を為す者，数理に明らかならず候，測に精しからずして能く至る有るものあらざるなり〉とみずから記している景佑は，ほかに類を見ない多くの著述を残している。…

※「《寛政暦書》」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