The 24 Solar Terms

The 24 Solar Terms is the product of ancient Chinese farming civilization. Agricultural production was closely related to the rhythm of nature. The Solar Terms system was created by ancient Chinese ancestors who followed the agricultural season by observing the movement of celestial bodies and recognizing the changing rules of seasons, climate, phenology and other aspects in one year.

On November 30, 2016, "The Twenty-Four Solar Terms" of China was inscribed by UNESCO on the Representative List of the Intangible Cultural Heritage of Humanity.

The origin of 24 Solar Terms in China

After the long-term observation of movement of the Sun, Moon and Big Dipper, the ancient Chinese adopted a lunisolar calendar, which has been unique in the whole world. 24 segments were divided according to the sun’s annual circular motion. Each segment is spaced 15° apart along the ecliptic and has a specific ‘Solar Term’. The calendar system has played a fundamental role in an agricultural society like China in the past thousands of years.

Twenty-Four Solar Terms originated in the Yellow River reaches of North China, which were created based on the changes of seasons, astronomy and phenology in this region and has been progressively applied nationwide. The Solar Terms begin with the Start of Spring and ends with the Greater Cold, moving in cycles.

The twenty-four solar terms can be divided into three groups:

One group reflects the seasonal changes (including 8 terms): Start of Spring, Start of Summer, Start of Autumn and Start of Winter mark the four seasons; Spring Equinox, Summer Solstice, Autumn Equinox, and Winter Solstice reflect the height changes of the sun from the astronomy aspect.

One embodies natural phenomena (including 4 terms): Insects Awaken, Pure Brightness, Grain Full and Grain in Ear.

The rest reflects the climate changes (including 12 terms): Slight Heat, Great Heat, The End of Heat, Lesser Cold and Greater Cold tell the temperature changes; Rain Water, Grain Rain, Light Snow and Heavy Snow reflect the precipitation levels; White Dew, Cold Dew and Frost Descent reflect the dropping process and degree of the temperature.

The date of each solar term is basically fixed with minor differences of within one or two days. Each month has two solar terms.

The twenty-four solar terms are the product of ancient agricultural civilization, which occupies an extremely important position in the Chinese traditional culture. The knowledge has been passed down from generation to generation and used traditionally as a timeframe to direct farming production and daily routines. It remains of particular importance to farmers for guiding their practices. Common people also follow the calendar to watch out weather changes and live a healthy life.

The 24 Solar Terms Traditions

In the daily life, almost every solar term requests people to have relevant eating habits (food material and cooking style). Based on the twenty-four solar terms, rich health-preserving customs have also been formed, such as the beginning of spring to nourish the liver, the beginning of summer to replenish water, the beginning of autumn and winter to nourish Yin inside body. At the same time, a large number of stories, legends, poems and songs have also been created according to the knowledge system, which focus on expressing people's thoughts, emotions and spiritual sustenance. Therefore, for Chinese people, the twenty-four solar terms are not only a time system, but also a useful guide to life.

List of 24 Solar Terms in 2021

The 24 solar terms are based on the position of the sun on the regressive ecliptic, that is, the annual movement of the sun is divided into 24 equal parts, and each 15° is 1 equal part. The 24 solar terms is an important part of Chinese lunar calendar.

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