Overview
Key data
| Item | Detail |
|---|---|
| Period of use | 1645 – 1911 CE |
| Compilers | Xu Guangqi (compiled), Johann Adam Schall von Bell (revised) |
| Innovation | The true solar term formally adopted |
| Year head | Jian-yin |
From the Chongzhen lishu to the Shixian calendar
In the late Ming, Xu Guangqi directed the compilation of the Chongzhen lishu, 46 works in 137 juan, bringing in Western astronomy and calendrics; it was not promulgated before the Ming fell.
In the early Qing, Johann Adam Schall von Bell condensed it to 103 juan for the court under the title Shixian shu; promulgated in 1645, it became the Shixian calendar.
The true solar term in the calendar
The Shixian calendar formally adopted the true solar term, replacing the mean terms used for a thousand years — the fifth great reform.
Mean terms divide the year by equal time; true terms by the sun’s actual arc along the ecliptic. After the change the dates of the terms were no longer fixed, and the placing of intercalary months shifted with them. Only then did the correspondence of the twenty-four terms to the sun’s true position stand written as it is.
Afterwards
The Shixian calendar was used to the end of the Qing. In 1912 the Republic adopted the Gregorian calendar while keeping the traditional one, which survives today as the “agricultural calendar.”
From the Taichu to the Shixian, the Chinese calendar passed through five great reforms, from rough to fine over two thousand years — a history of unceasing measurement and correction.
Compiled and arranged by Chujia Kuang.