Nagahide SASAKI (later Hidenaga YOSHIDA) became the assistant of Tadataka NISHIKAWA, a son of Masayoshi NISHIKAWA, at the time of Horyaku calendar revision (Horyaku Calendar).
佐々木長秀（後に吉田秀長）が宝暦の改暦（宝暦暦）の際に西川正休の息子西川忠喬の作暦手伝となる。