Paul Yachita Tsuchihashi (, 土橋 八千太 Tsuchihashi Yachita, 1866-1965)  S.J. was a Japanese Roman Catholic priest, mathematician, astronomer, Sinologist, lexicographer, academic and administrator. Father Paul is known for having developed extensive tables for converting traditional  Japanese era dates into Gregorian calendar equivalents — compare, e.g.,  Calendrical Time Conversion Table which is derived from a formula for determining the numbered date in the Japanese month. 
After completing studies in Paris, Tsuchihashi was assigned to
Shanghai and the observatory at She Shan Hill (Zose). In this period, his work focused on the movement of asteroids. He also taught mathematics at the Jesuit  Aurora University in Xujiahui.
When Sophia University was established in Tokyo in 1913, he became one of the members of the teaching faculty. He taught mathematics and Chinese literature. He was Rector of the university from 1940 until the end of the war years.
In a statistical overview derived from writings by and about Paul Tsuchihashi,
OCLC/ WorldCat encompasses roughly 10+ works in 20 publications in 3 languages and 200+ library holdings.
Japanese chronological tables from 601 to 1872 (, 1952 邦曆西曆對照表: 自推古九年至明治五年 Hōreki seireki taishōhyō: Suiko kyūnen yori Meiji gonen ni itaru) OCLC 001291275
^ Library of Congress authority file,
Paul Yachita Tsuchihashi, no2009-35643
^ "98-Year-Old Jesuit Priest, Born a Samurai Warrior, Dies at Tokyo University,"
Black Belt, p. 60, at (US). Vol. 3, No. 7 (July 1965), p. 60. Google Books
NengoCalc (University of Tübingen), Tsuchihashi conversion tables
^ Totman, Conrad D. (1980).
The Collapse of the Tokugawa Bakufu, 1862-1868,, p. 484, at p. 484. Google Books
^ Webb, Herschel
et al. (1994). Research in Japanese Sources: a Guide, pp. 20-27.
^ Vallina, Agustín Udías. (2003).
Searching the Heavens and the Earth: the History of Jesuit Observatories,, p. 278, at p. 278. Google Books
^ a b Vallina,
, p. 164, at p. 164. Google Books
WorldCat Identities: 関孝和 ca. 1642-1708
Totman, Conrad D. (1980).
The Collapse of the Tokugawa Bakufu, 1862-1868. Honolulu: University of Hawaii Press. ISBN 9780824806149; OCLC 185964275 Webb, Herschel and Marleigh Grayer Ryan. (1994). Research in Japanese Sources: a Guide. Ann Arbor, Michigan: University of Michigan Press. ISBN 9780939512652; OCLC 29913782