The Chongzhen calendar () or Shixian calendar () was the final

lunisolar A lunisolar calendar is a calendar in many cultures, combining lunar calendars and solar calendars. The date of Lunisolar calendars therefore indicates both the Moon phase and the time of the solar year, that is the position of the Sun in the Ea ...

Chinese calendar The traditional Chinese calendar (also known as the Agricultural Calendar ��曆; 农历; ''Nónglì''; 'farming calendar' Former Calendar ��曆; 旧历; ''Jiùlì'' Traditional Calendar ��曆; 老历; ''Lǎolì'', is a lunisolar calendar ...

. It was developed by the Jesuit scholars

Johann Schreck Johann(es) Schreck, also Terrenz or Terrentius Constantiensis, Deng Yuhan Hanpo 鄧玉函, Deng Zhen Lohan, (1576, Bingen, Baden-Württemberg or Constance – 11 May 1630, Beijing) was a German Jesuit, missionary to China and polymath. He is ...

and

Johann Adam Schall von Bell Johann Adam Schall von Bell (1 May 1591 – 15 August 1666) was a German Jesuit, astronomer and instrument-maker. He spent most of his life as a missionary in China (where he is remembered as "Tang Ruowang") and became an adviser to the Shunz ...

with

Xu Guangqi Xu Guangqi or Hsü Kuang-ch'i (April 24, 1562– November 8, 1633), also known by his baptismal name Paul, was a Chinese agronomist, astronomer, mathematician, politician, and writer during the Ming dynasty. Xu was a colleague and collaborato ...

from 1624 to 1644, and was dedicated to the

Chongzhen Emperor The Chongzhen Emperor (; 6 February 1611 – 25 April 1644), personal name Zhu Youjian (), courtesy name Deyue (),Wang Yuan (王源)，''Ju ye tang wen ji'' (《居業堂文集》), vol. 19. "聞之張景蔚親見烈皇帝神主題御諱字德� ...

. When he died a year after it was released, it was propagated in the first year of the

Qing dynasty The Qing dynasty ( ), officially the Great Qing,, was a Manchu-led imperial dynasty of China and the last orthodox dynasty in Chinese history. It emerged from the Later Jin dynasty founded by the Jianzhou Jurchens, a Tungusic-speak ...

by the

Shunzhi Emperor The Shunzhi Emperor (15 March 1638 – 5 February 1661) was the second emperor of the Qing dynasty of China, and the first Qing emperor to rule over China proper, reigning from 1644 to 1661. A committee of Manchu princes chose him to succe ...

, who changed its name to Shíxiàn calendar. The calendar was used from the early Qing period into the modern era. The main changes introduced by the calendar are: * Replacement of the original "平气法"

solar term A solar term is any of twenty-four periods in traditional Chinese lunisolar calendars that matches a particular astronomical event or signifies some natural phenomenon. The points are spaced 15° apart along the ecliptic and are used by lunisola ...

system (based on dividing a tropical year equally) with one based on the

ecliptic longitude The ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions, orbits, and pole orientations of Solar System objects. Because most planets (except Mercury) and many small Solar System b ...

of the sun ("定气法"). * Placement of intercalary months changed to accommodate the changes in the solar term system.

References

Xu Guangqi Specific calendars {{China-hist-stub