Last revised: 2026-10-18
3 · Solar terms and phenology
| English | 中文 | Gloss | Termonline |
|---|---|---|---|
| the Twenty-Four Solar Terms | 二十四节气Calendrical terms · solar terms | Twenty-four markers on the sun’s path, roughly fifteen degrees apart. | — |
| node (major solar term) | 节Calendrical terms · solar terms | The twelve terms that fall at the head of a month and mark its boundary: Lichun, Jingzhe and the like. | — |
| breath (mid-term) | 中气／气Calendrical terms · solar terms | The twelve that fall in mid-month: Yushui, Chunfen and the like. Node and breath alternate; together they make the twenty-four. | near: 中气Astronomy · History of Astronomy |
| instant of a solar term | 交节时刻Calendrical terms · solar terms | The instant the sun reaches a given degree of the ecliptic. An instant, not a whole day. | — |
| solar longitude | Ecliptic lon.Fundamentals · coordinates | The sun’s angle along the ecliptic measured from the vernal equinox. The solar terms are its round-number marks. | TermonlineAstronomy · Astrometry · 2024 |
| the eight principal terms | 分至启闭Calendrical terms · solar terms | The eight terms fixed earliest: the two equinoxes and two solstices, plus the four “beginnings” of spring, summer, autumn and winter. | — |
| mean solar term | 平气Calendrical terms · solar terms | Fixing the terms by dividing the tropical year into twenty-four equal parts — the method of those who did not know the sun moves unevenly. It went with the mean new moon. | — |
| true solar term | 定气Calendrical terms · solar terms | Fixing the terms by the sun’s actual degrees along the ecliptic. The Shixian Calendar introduced it, and it is still in use. | — |
| phenological period | 候／物候Calendrical terms · solar terms | The solar term is where the celestial ruler has reached; the phenological period is what you see on the ground. The latter lags by about a month. | — |
| phenological sign | 候应Calendrical terms · solar terms | The natural sign assigned to each of the seventy-two periods — thawing east winds, peach trees in flower. They are drawn from plants, from animals, and from inanimate nature. | — |
| the seventy-two periods | 七十二候Calendrical terms · solar terms | Each solar term split into three periods of about five days, seventy-two in all. The full record is in the “Shixun jie” chapter of the Yizhou shu. | TermonlineAstronomy · History of Astronomy · 2024 |
| awakening of the dormant | 启蛰Calendrical terms · solar terms | The older name of the term now called Jingzhe. Under Emperor Jing, whose personal name was Qi, it was rewritten; the two words mean the same thing. | — |
| monthly ordinances | 月令Institutions · sources | The genre that sets out, month by month, the sky, the signs on the ground and the acts of government. The “Yue Ling” of the Book of Rites is its model and the solar terms’ ancestor. | — |
| the three fu | 三伏Calendrical terms · solar terms | The three hottest stretches of the year, counted from the third geng day after the summer solstice. It is reckoned by stem-branch days, a scale parallel to the solar terms. | — |
| the nine nines | 九九Calendrical terms · solar terms | Nine-day stretches counted from the winter solstice, eighty-one days in all — a popular scale for the cold and a common note in almanacs. | — |
| the day of the earth god | 社日Calendrical terms · solar terms | Twice a year, on the fifth wu day after the beginning of spring and of autumn — reckoned, like the fu, by stem-branch days. | — |
| solar terms entered in the almanac | 节气注历Calendrical terms · solar terms | Entering the twenty-four terms day by day in the almanac. The Taichu Calendar was the first to carry them in full; the Shixian Calendar began to use the true terms. | — |
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