Semmyō calendar (宣明暦 Semmyō-reki), also known as Semmei-reki or Xuanming li, was a Japanese lunisolar calendar (genka reki). It was used from the late-9th century to the late-17th century.
The Semmyō-reki or Semmei-reki system corrected errors in earlier calendars which were developed in China. It was the work of Shibukawa Shunkai and Shikokawa Kōkyō.
The earliest record of this calendar is in the 8th month of the 3rd year of Jōgan (861) during the reign of the Emperor Seiwa.
- ↑ Nussbaum, Louis-Frédéric. (2005). "Calendar" in Japan Encyclopedia, pp. 98-99.
- ↑ Nussbaum, "Semmei-reki" at p. 840; Bramsen, William. (1880). Japanese chronological tables, p. 25.
- ↑ Needham, Joseph. (1959). Science and civilisation in China, Mathematics and the sciences of the heavens and the earth, Vol. 3, p. 391 note d.
- ↑ Nussbaum, "Shibokawa Shunkai" at pp. 850-851.
- ↑ Japan, Monbushō. (1876). An outline history of Japanese education: prepared for the Philadelphia International Exhibition, 1876, p. 160.