The 24 Solar Terms (二十四节气 in Chinese) are a traditional Chinese calendar system that divides the solar year into 24 equal segments based on the sun’s position in the zodiac.
It was inscribed on the UNESCO Representative List of the Intangible Cultural Heritage of Humanity in 2016, recognizing their cultural significance and the role they play in guiding agricultural practices and daily life in China.
The 24 Solar Terms show the relationship between universe, season, climate and agriculture, which is a unique creation by Chinese ancestors. To date, it has functioned as a complete set of weather calendars to guide the agricultural production in China. Each solar term reflects specific astronomical and climatic phenomena, offering insights into the best times for planting, harvesting, and other agricultural practices.
At the initial stage of agricultural development, people began to explore the seasonal rule in agricultural production to meet the needs in seeding, harvesting and other activities. Gradually, there formed the concept of “Seed in Spring, Grow in Summer, Harvest in Autumn and Store in Winter”.
During the Spring and Autumn Period (770–476 BC), agricultural production was highly subject to the seasonal changes with the invention of iron tools, thus forming the concept of Solar Term. Tugui (土圭), a tool developed at that time, was used to measure the shadow of the sun for determining the solar terms.
Astronomically, the 24 Solar Terms are defined according to the position of the sun on the ecliptic. 0 degree of celestial longitude is the Spring Equinox, and every following 15 degrees marks a solar term, forming a full 350 degrees with the 24 Solar Terms.
As time went on and China started connecting with nearby countries, the 24 Solar Terms were introduced into North Korea, Japan and other neighboring countries. During the Edo Period (1603–1867), Japan began to adopt the Twenty-four Solar Terms, which have been used till now.
In modern times, the 24 Solar Terms are still an important part of Chinese culture and everyday life of Chinese people. Some traditions related are still followed as a daily routine, and we still benefit from these ancient wisdoms.
We’ll dive deep into each of the Solar Terms in later pieces of this series to learn about their meanings, and how we can live by such ancient knowledge that concludes the essence of how the world around us changes.
As we’re approaching summer, we will start from the one that’s closest to present. Stay tuned for our upcoming posts! Let us live by the natural flow.