The Chongzhen calendar () or Shixian calendar () was a historical edition of the
lunisolar Chinese calendar
The traditional Chinese calendar, dating back to the Han dynasty, is a lunisolar calendar that blends solar, lunar, and other cycles for social and agricultural purposes. While modern China primarily uses the Gregorian calendar for officia ...
from 1645 to 1913.
It was developed by the lead of
Xu Guangqi with the assistance of the Jesuit scholars
Johann Schreck and
Johann Adam Schall von Bell from 1624 to 1644, and was dedicated to the
Chongzhen Emperor. 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 Dynasties of China, imperial dynasty of China and an early modern empire in East Asia. The last imperial dynasty in Chinese history, the Qing dynasty was preceded by the ...
by the
Shunzhi Emperor, who changed its name to Shíxiàn calendar.
This calendar is notable for systematically introducing the concepts and development of European mathematics and astronomy to China for the first time, and constituted the first major collaboration between scientists from Europe and from the Far East.
Documented in more than 100 volumes of books, It offered an encyclopedic account of
Euclidean geometry
Euclidean geometry is a mathematical system attributed to ancient Greek mathematics, Greek mathematician Euclid, which he described in his textbook on geometry, ''Euclid's Elements, Elements''. Euclid's approach consists in assuming a small set ...
,
spherical geometry and
trigonometry
Trigonometry () is a branch of mathematics concerned with relationships between angles and side lengths of triangles. In particular, the trigonometric functions relate the angles of a right triangle with ratios of its side lengths. The fiel ...
, with extensive translations and references to
Euclid's Elements
The ''Elements'' ( ) is a mathematics, mathematical treatise written 300 BC by the Ancient Greek mathematics, Ancient Greek mathematician Euclid.
''Elements'' is the oldest extant large-scale deductive treatment of mathematics. Drawing on the w ...
and the works of
Nicolaus Copernicus,
Johannes Kepler
Johannes Kepler (27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, Natural philosophy, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best know ...
,
Galileo Galilei
Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642), commonly referred to as Galileo Galilei ( , , ) or mononymously as Galileo, was an Italian astronomer, physicist and engineer, sometimes described as a poly ...
, and
Tycho Brahe, whose
Tychonic system was used its main theoretical basis. In addition, a comprehensive set of
mathematical tables and astronomical
ephemerides was included.
The main changes introduced by the calendar are:
* Replacement of the original "平氣法"
solar term system (based on dividing a tropical year equally) with one based on the
ecliptic longitude of the sun ("定氣法").
* Placement of intercalary months changed to accommodate the changes in the solar term system.
This calendar was used from the early Qing period into the early modern era, but was modified and replaced in 1914 and again in 1928,
with various minor modifications since then. In 1928, it was put under the management of
Purple Mountain Observatory
The Purple Mountain Observatory (), also known as Zijinshan Astronomical Observatory, is an astronomical observatory located on the Purple Mountain in the east of Nanjing. The observatory is responsible for calculating the official Chinese calen ...
(Zijinshan Astronomical Observatory), thus the present version is popularly referenced to as the Zijin calendar. All of these editions were based on modern astronomical data. In the People's Republic of China, it has been officially standardized as GB/T 33661-2017, "Calculation and Promulgation of the Chinese Calendar", issued by the
Standardization Administration of China on May 12, 2017.
References
Xu Guangqi
Specific calendars
1634 establishments in Asia
* , now at University of Oslo
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