Paul Yachita Tsuchihashi (土橋 八千太, Tsuchihashi Yachita, 4 December 1866 – 3 March 1965) SJ was a Japanese Roman Catholic priest, mathematician, astronomer, Sinologist, lexicographer, academic and administrator.[1] Father Paul is known for having developed extensive tables for converting traditional Japanese era dates into Gregorian calendar equivalents[2] — compare, e.g., Calendrical Time Conversion Table[3] which is derived from a formula for determining the numbered date in the Japanese month.[4]