What is 24 Solar Terms (二十四节气)?
The 24 solar terms (二十四节气) are a traditional Chinese calendar system that divides the solar year into 24 periods of approximately 15 days each, based on the sun's position in the zodiac. Formalized during the Han dynasty and recorded in the Huainanzi (139 BCE), each term reflects seasonal changes in climate, agriculture, and natural phenomena. The system was declared a UNESCO Intangible Cultural Heritage in 2016. Unlike the lunar calendar, solar terms are based on the tropical year — the same astronomical foundation as the Western calendar.
The 24 solar terms divide the year according to the sun's position, guiding agriculture and daily life.
— Huainanzi, Chapter 3 (Liu An)
Key Takeaways
- The terms divide the year at intervals tied to the sun's longitude — starting with Lichun (立春, Start of Spring) in early February and running through the eight key points of Lichun, Chunfen (春分, Spring Equinox), Lixia, Xiazhi, Liqiu, Qiufen, Lidong, and Dongzhi — giving farmers precise planting windows within the agricultural year.
- Chinese: 二十四节气 (24 Solar Terms).
Understanding 24 Solar Terms
The 24 solar terms anchor the Chinese agricultural year to the tropical year rather than to the phases of the moon, which is why they stay tied to roughly the same Gregorian dates every year. Each term marks a point on the sun's annual path through the sky: the even-indexed ones are the twelve "major" terms such as Chunfen (春分, Spring Equinox) and Dongzhi (冬至, Winter Solstice), while the odd-indexed ones such as Yushui (雨水, Rain Water) and Bailu (白露, White Dew) describe the shifting weather. The terms originated along the Yellow River (黄河) basin and were already listed in the Huainanzi (139 BCE), compiled at the court of Prince Liu An. They were traditionally used to time sowing, harvesting, and the seasonal routines of daily life, and the system was inscribed on the UNESCO list of Intangible Cultural Heritage in 2016.
Further Reading
Frequently Asked Questions
What is 24 Solar Terms in Chinese Philosophy?
The 24 solar terms (二十四节气) are a traditional calendar system that divides the tropical year into 24 periods of roughly 15 days each, keyed to the sun's position along the zodiac rather than to the moon's phases. Because they follow the sun, each term falls on nearly the same solar date every year, which is what makes them a reliable agricultural calendar.
What does 二十四节气 mean?
二十四节气 (èrshísì jiéqì) literally means "twenty-four seasonal nodes." The name reflects the system's origin along the Yellow River basin, where it was used to time plowing and harvest; the terms were already set down in the Huainanzi (139 BCE) and were later formalized by the Han dynasty.
Why is 24 Solar Terms important?
Because the 24 solar terms track the sun rather than the moon, they stay aligned with the seasons and so have guided Chinese farming for over two millennia — inscribing terms such as Qingming (清明, Clear and Bright) into the names of festivals. The system was recognized as a UNESCO Intangible Cultural Heritage in 2016, and the terms still appear on Chinese calendars used for agricultural and cultural reference today.
Also Known As
Chinese: 二十四节气. 二十四节气, Ershisi Jieqi