Jōkyō calendar

Japanese lunisolar calendar
Jōkyō calendar published in 1729. Exhibit in the National Museum of Nature and Science, Tokyo, Japan.

The Jōkyō calendar (貞享暦, Jōkyō-reki) was a Japanese lunisolar calendar, in use from 1684 to 1753.[1] It was officially adopted in 1685.[2]

History

The Jōkyō-reki system was developed and explained by Shibukawa Shunkai.[3] He recognized that the length of the solar year is 365.2417 days.[1]

Shibukawa discovered errors in the traditional Chinese calendar, the Senmyō calendar, which had been in use for 800 years.[3]

See also

  • Japanese calendar
  • Sexagenary cycle
  • Jōkyō

References

  1. ^ a b Nussbaum, "Jōkyō-reki" at p. 431; "Teikyō-reki" at p. 431
  2. ^ Orchiston, Wayne et al. (2011). Highlighting the History of Astronomy in the Asia-Pacific Region, p. 155.
  3. ^ a b Nussbaum, "Shibukawa Shunkai" at pp. 850–851.

External links

  • National Diet Library, "The Japanese Calendar" -- historical overview plus illustrative images from library's collection
  • v
  • t
  • e
Japanese calendar
  • Genka calendar 692–696
  • Gihō calendar 697–763
  • Taien calendar 764–862
  • Goki calendar 858–861
  • Semmyō calendar 862–1685
  • Jōkyō calendar 1685–1755
  • Hōryaku calendar 1755–1798
  • Kansei calendar 1798–1844
  • Tenpō calendar 1844–1872
  • Gregorian calendar 1873–present