On Track with the Sun--The 24 Solar Terms
Laura Li / photos Vincent Chang / tr. by Brent Heinrich
October 1994

Lots of people listen to the weather report every day, but you probably didn't know that the Central Weather Bureau operates an astronomical observatory which is not devoted to predicting the weather. It is responsible for calculating the precise timing of the 24 Solar Terms of the Chinese calendar every year. And after examining the data, the Ministry of the Interior includes it in the annual farmer's almanac, distributed every year to each agricultural worker.
But just what are the Chinese Solar Terms? Almost every Chinese person has heard mention of them, but very few have a clear idea of what they are. In this edition, we hope to enlighten our readers on their origins and development, and by introducing a number of interesting customs to rekindle the wisdom of the ancient Chinese.
In a fashionably decorated Taipei bookstore, a customer wanted to locate some information concerning the Chinese "Solar Terms." The saleslady brought out several books which discussed Chinese folk festivals. The prospective buyer explained that "Solar Terms" did not include the Mid Autumn Festival when people gaze at the moon, or Dragon Boat Festival when people gobble rice cakes; the 24 Solar Terms include "the Awakening of Insects," "the Husks of Grain," "White Dew," and "the Descent of Hoar Frost." When the young girl heard this, with a mystified expression on her face she said that they had no books like that.
Aren't the 24 Solar Terms listed year after year in the Chinese farmer's almanac, the one old grannies flip through every day to calculate the weather? The average urbanite, whose conception of solar cycles stops at "If you get too much sun you'll blemish your skin," has already forgotten why the Chinese word for "day" is really the character for "sun."

The 24 Solar Terms Fixed Along the Earth's Orbital Plane (Data courtesy of Liu Chao-min, Civil Aeronautics Administration Meteorological Center) (Drawing by Lee Su-ling)
Putting the sun in the lunar calendar
As far as calendars go, your granny might not be completely on target either. She would almost surely tell you, "The Chinese national calendar is Yang (sun) reckoning, and the old-style calendar is Yin (moon) reckoning." But this statement fails to capture the peculiar truth: The calendar that the civil authorities publish every year is derived from the West and should not rightfully be called the "Chinese national calendar." Furthermore, that old-style (farmer's) calendar that old wives know so intricately is not entirely based on the movements of the moon.
The agricultural calendar is not exclusively the lunar calendar; it combines lunar and solar elements. And the 24 Solar Terms which make up such an important part of the calendar are 100% compliant with the movements of the sun. Why would the early Chinese who based their social life around a lunar schedule designate an extra annual cycle of 24 solar periods?
The explanation is very simple: the ancients gathered their knowledge completely from nature; they inferred a direct relation between the waxing and waning of the natural world and the birth and death of every human being. When would the fish swim up to the water's surface through the broken ice? When would the swallows arrive? When would the crops bloom and wither? Furthermore, when could they expect a heat wave, so they might be extra cautious about the spread of contagious disease? When would the frosts come again, so that all the farmers, fishers and hunters could stock up food for the winter? Every last one of these concerns was decided not by the moon but by the sun, by the length and power of the sunlight!
To China, founded as it was on agriculture, the importance of sunlight could hardly be greater. Because of this, integrating information concerning the movements of the sun into the lunar calendar for the consideration of the farming folk was an impressive feat of learning. As early as the Hsia Dynasty 4000 years ago, the ancient Chinese observed the shadows of the sun and discovered the summer solstice--when the sun's shadow is the shortest and the daylight lasts the longest--and the winter solstice --when the sun casts the longest shadow and daylight is least. These dates became the starting points of the system of 24 terms.
Besides astronomical observations, the Hsia Dynasty also established the Hsia Hsiaocheng, a meteorological booklet which cryptically recorded climatic and biological phenomena. Though consisting of a mere 463 characters, the Hsia Hsiaocheng may count as China's earliest seasonal almanac.
For example, the first two phrases under the first month of the year in the Hsia Hsiaocheng are "Open hibernation. Geese north villages." The meaning is that during the first month, insects that hibernate during the winter will begin to awaken, and wild swans and geese will fly back to villages in the north. Entered under the second month is "Blossoms. Plants color. Pluck abundance. Rue blooms," thus reminding everyone that the wild plants are in blossom and to go to the fields and gather them. Three thousand years ago the manifestation of the insects, birds and plants along the Yellow River valley was in this way eloquently and succinctly sketched out.

The beginning of June falls right in the middle of the Solar Terms "Little Fullness" and "Husks of Grain"; the annual harvest of wheat in northern China has already grown sturdy and ample. The photo was taken in mainland China's Shandong Province.
Five days in a phase, three phases in a term
Following this kind of observation, more than 1000 years elapsed step by step, up to the Spring and Autumn Period, when the ancients established the two days of the year in which "day and night are equally long," which are known in astronomy as the vernal and autumnal equinoxes.
It was not only at this time that "spring" and "autumn" were precisely defined. At the same time Lu-Shih Ch'un-Ch'iu (The Spring and Autumn Annals of Mr. Lu) and Li Chi (Record of Ritual), inheriting the tradition of the Hsia Hsiaocheng, recorded the monthly changes in the natural world. In them can be found such phrases as "Rain water begin," "Solstice of the lesser heats" and "White dews descend," obviously embryonic forms of the Solar Terms.
From a modern perspective, the ancient Chinese used the Solar Terms to integrate astronomical and meteorological observations. They have a scientific derivation--the earth rotates at a tilted angle as it orbits around the sun. According to the different position of each location on the globe, the sun's rays will land at correspondingly different angles, and in this way the alternating seasonal cycle of winter, spring, summer and autumn is produced. This in turn influences the precipitation and temperature at the earth's surface. In other words, the Solar Terms established a number of dates based on astronomical phenomena, but at the same time they came to reflect climatic conditions and changes in the natural environment.
To attain even greater precision, the four so-called "commencement days" (at which spring, summer, fall and winter begin) were eventually inserted in between the two solstices and the two equinoxes. This system was developed even further around the Western Han Dynasty, when the ancient Chinese, knowing that the earth makes an orbit of 360 degrees around the sun, designated a Solar Term for every 15 degrees. They further selected a name for each term, based on its special climatic characteristics, thus establishing the standard 24 Solar Terms.
The Solar Terms are designated according to the position of the earth relative to the sun. Therefore each Solar Term has a basically fixed date on the solar calendar. For instance, every year the winter solstice falls between the 21st and the 23rd of December. The summer solstice falls between June 21st and 23rd. And on the average, a new Solar Term arrives once every 15 days. Perhaps the ancients felt that "five days make a phase, and three phases make a term"--every half month the natural environs will shift in some way, and it's best to make note of it.

The shed cicada shell is a symbol of the arrival of summer in Taiwan.
Planning your day by the Solar Terms
The 24 Solar Terms comprise a rough solar calendar, but the ancient Chinese commonly used a lunar calendar. The two systems operated on different foundations and are constitutionally incompatible. In meshing 24 solar terms with a lunar calendar, the ancient Chinese performed an impressive feat. It is just that after these dates were seamlessly inserted into the lunar calendar, all the grannies have borrowed its wisdom without realizing it and without ever considering the uncanny mystery of splicing the sun with the moon.
To make it easier to understand and remember, the ancients gave each term a very accessible name (see accompanying table). Besides the two solstices, the two equinoxes and the four "commencement days," several term names clearly delineate changes in the temperature, such as the "Lesser Heat," "Great Heat" and "Bounds of Heat" during the summer and fall or the "Lesser Cold" and "Great Cold" during winter. Other term names, such as "Rain Water," "White Dew," "Cold Dew," "the Descent of Hoar Frost," "Lesser Snow" and "Great Snow," suggest the likely climatic conditions during that time of year. Still others depict phenomena among nature or biology, such as "the Awakening of Insects," "Clear and Bright," "Little Fullness" and" the Husks of Grain."
After 2000 years of exposure to such ingenuity, the Solar Terms have deeply permeated the lives of the Chinese people. At the same time they serve to remind the farming folk not to grow too muddle-headed gazing at the moon; lift up your heads toward the sun, take advantage of the bright light of day. When the time has come to sow seeds or transplant rice seedlings, to raise silkworms or gather wild plants, absolutely don't miss the right season!
The original content of the 24 Solar Terms was very simple, but over many years, they slowly developed into focal points for an extremely fertile cultural milieu. They are guides to farming life, reference dates for weather forecasting and holidays for all sorts of ceremonial activities. Almanacs, the weather, agriculture, the general life of the community--all abide under the shadow of the Solar Terms!

ROC 1994 Seasonal Calendar.
The ancient wisdom of respecting nature
Of course, for the average modern person in an air conditioned room who has never worried about heat waves or cold spells, who cannot even distinguish night from day from his vantage point in a karaoke club, and who has always been unclear as to when the rice in his dish was transplanted and reaped, the 24 Solar Terms are of no practical use whatsoever. The original system of strengthening the lunar calendar is of no avail either. Modern people don't use the lunar calendar anymore; they directly look at the watches on their wrists. Year, month, day, minute and second are all precisely measured, a vast improvement on the ancients who could only split up the year into 24 parts!
Those who think this way have not stopped to reflect on the position and impact that the Solar Terms had upon the life of the early Chinese. This impact comes from the reverence they held for nature, which expressed the ancient people's wish to remain in harmony with nature, with the respectful intent of procuring reciprocal consideration. This was the cosmic philosophy of "The time according to the heavens, the deed according to the time."
The ancient customs surrounding the Solar Terms are numerous. Many of them have been abandoned and lost, but fortunately a rich heritage of poems and songs can provide a distant reverie of the past.
For instance at the arrival of the "Commencement of Spring" (the beginning of February), despite the fact that the whole outdoors was covered in ice, farming families could all rest assured that spring was not far away. If provisions were running low, they would pluck up their courage to face the cold and hunger, and they might also calculate the remaining days until spring and relax a little. And on the day before the "Commencement of Spring," the ancient emperors would lead all the civil and military officials in a procession. Wearing green clothes and green hats, they would march in pomp and majesty to the eastern quarter of the capital city to "welcome the spring."
On the precise day of "Commencement of Spring," every town and hamlet would hold the ceremony of "beating the spring cow." They would carry out a clay model of a cow, and smash it open with sticks painted in the five ceremonial colors of blue, yellow, red, white and black. Then they would pull from its belly a smaller model cow that was placed there in advance, and at that time everyone would compete at grabbing the pieces of smashed spring cow, in hopes of gaining the luck of the new year.
Such fascinating rituals as "beating the spring cow" were unquestionably meant to rouse the farming folk: when spring arrived, they needed to get out and organize agricultural activities. Because they worried that the old cows might have become too lazy after resting for a whole winter, they cudgeled a "spring cow." People and livestock alike came out and loosened up their muscles and bones for a while. Today "Commencement of Spring" has been renamed "Farmer's Day," but no one welcomes spring or beats any spring cows. The festive flavor has been lost.
Another spring holiday which better retains its holiday spirit is "Clear and Bright" (or Chingming), at the beginning of April. It is called "Clear and Bright" to express that spring has arrived in full bloom; the sky is clear and the air is crisp; the whole land appears especially beautiful and vivid. According to the description of the ancients, this Solar Term is "Paulownia become majestic. Field mice become quail. Rainbows appear." This means that many white clusters of flowers blossom on the paulownia trees that cover the mountainsides; field mice disappear, having turned into quail (in fact a misconception); and rainbows begin to appear in the sky.
In order not to waste the colorful, gorgeous spring, at the arrival of the "Clear and Bright" Solar Term, the early Chinese would venture out of town to worship the ancestors and tidy their tombs. Along the way they made a spring outing out of it. The children would fly kites, men would shoot arrows, and women would swing on swing sets. In modern times the "Clear and Bright" Solar Term has been designated as "Tomb Sweeping Day." It is a holiday for relaxing, and it is one of the few Solar Term which retains a festive spirit.

In the middle of July, after the first crop of rice is harvested, farmers can only take a short breather, before they start in on the second crop of rice. (Sinorama file photo)
Of silk and ships
The several following Solar Terms have even more of a vital farming flavor. For instance, the significance of "Grain Rains" is obvious from its name, that is, rains make many different kinds of grains sprout. The hope is that the rice might rely on the moistening of spring rains to grow tall. Also during the Grain Rains, "Hoopoes descend on mulberries." Hoopoes, birds of the family Upupidae, at this time rest on the branches of mulberry trees, and this is a reminder for farming wives to gather up mulberry branches in preparation for raising silkworms.
"When the Grain Rains arrive, draw the silkworm close." This was how the literati of the Ching Dynasty described the scene all over China south of the Yangtze River, where every household cautiously closed the doors of their homes and did not allow visiting from house to house. Surprisingly, they did this for fear that the baby silkworms might be disturbed. The silkworms grew bigger and bigger, and a little more than a month later, the silkworms start to spin their cocoons. At this time, be careful not to let the cocoons sit too long, because "After the Little Fullness, silkworms have no silk." This reminds the farm wives that when the Solar Term "Little Fullness" arrives (around May 20), they should boil the silkworm cocoons in water and afterward pull out the silk and spin it.
One month after the Little Fullness is the summer solstice. The summer solstice is the point at which daylight is the longest and night is the shortest, and from the Chinese perspective this indicates that the potency of the sun is at its height. From now on it will begin to diminish; the Yang will lessen and the Yin will increase. So the summer solstice is also given a very arcane description: "Yin and Yang compete for death and life." (The moon is viewed as being a Yin force, and the sun is viewed as a Yang force.) This completely reflects the ancient Chinese world view based upon balancing negative and positive forces and the contrapositioning of the five elements (water, fire, wood, metal and earth).
The summer and winter solstices are the oldest of Chinese holidays. Evidence suggests that during the Han Dynasty the military and civil officials all took a day off on the summer solstice, returning home to bathe and to gather together with their families for a while. There is also a saying, "Wonton at the winter solstice, noodles at the summer solstice." After half a year of eating steamed sorghum bread they were able to enjoy a big feast of noodles.
Enjoy a good bath and a big banquet and make your body clean and fresh, to get ready for what follows: the harsh and torrid period of the Lesser Heat and the Great Heat. Only after the Bounds of Heat at the beginning of autumn could one breathe a sigh of relief.
Under the rainy conditions of the Great Heat, with its high temperatures and high humidity, contagious diseases could spread rapidly. Because of this, those who lived along the coast developed the custom of sending "the Great Heat Ship" out to sea. Just like the tradition of "burning the king's boat" in Taiwan, its purpose was to symbolically urge the gods of disease to go away, and also to remind everyone not to get slipshod with summer hygiene.

Black mullet is the treasure of Taiwan's fisheries industry. All the fishing folk of Kaohsiung know that the period for harvesting mullet roe is only ten-odd days long, falling at the time of the winter solstice. If they can manage a bountiful harvest, they can enjoy a good winter.
The busy autumn; festivals of reaping
In northern China, where the four seasons are distinct, summer is incredibly hot, but once the Commencement of Fall arrives, "Cool breezes pass. White dews descend. Cold cicadas drone." This points out that cool days are not far in the offing. Similarly to the Commencement of Spring, the emperor would lead the court officials to the western quarter of the capital city to "welcome the fall." At this time the autumn farming activities went into a phase of decline, and in the north the weather turned cold. There was always some fear that barbarian tribes might "descend south to graze their horses." At this time everyone began to brush up on their martial skills, even actively going out to kill the barbarians or steal the fat horses and goats that they raised!
Fall is the Chinese people's season of war. In the Ming and Ching Dynasties, formal military parades were held on the Descent of Hoar Frost (around October 12). On this day they paid honor to the flag god and inspected the military troops. "Swords and spears bright as snow, banners bright and colorful" accompanied the cold, harsh autumn. It truly carried a sad chill: "The brave warrior goes off, never to return"!
Fall passes and winter arrives. In the Chinese language, the original meaning of "winter" was "the end." It is the season when all life ceases its motion. "The water begins to ice, and the ground begins to freeze." "The Lesser Snow covers the earth; the Great Snow covers the rivers." All kinds of animals look for a place to take shelter from the cold. The sky is wintry, the ground frozen. Only the winter wheat, planted in the deep autumn of the "Cold Dew," is nurtured in the earth, in hope that come spring of next year it will sprout and grow tall.
Winter solstice--birth of the sun
Before the 24 Solar Terms draw to a close, there is still one day that calls for a big celebration--the winter solstice.
According to the observation of the ancients, "Winter solstice day, earthworms join. Five days later, elk horns free. Five days more, water springs move." Translated into common speech, the day of winter solstice is bitterly cold, so frigid that the worms in the ground cluster together for warmth, becoming tangled up in knots. But don't worry. After the winter solstice, the influence of the moon diminishes, and that of the sun increases. Five days after the winter solstice, the elks, considered by the Chinese to be "Yin beasts," will shed their horns upon feeling the increase in Yang energy. Five more days later, the frozen spring waters begin to melt.
Inevitably, on the winter solstice the emperor went to the edge of the capital to perform a ceremony in which he paid homage to the day and the first emperor of China. Among the common folk, every household lit ceremonial incense, revealing again the emphasis that the early Chinese placed on worshipping the heavens and ancestors. Other than that, winter solstice meant a three-day holiday. Everyone put on new clothes and prepared delicacies to eat, to usher in "winter solstice's auspicious new year." On this day northerners ate wonton, and southerners ate dumpling soup. Both dishes are round in shape as symbols of completion and full fortune.
In accordance with the early Chinese belief that in everything new meaning is derived from invisible qualities, the winter solstice represented the climax of Yin power, at which point the physical polarity must be reversed. Because of this "the winter solstice is the birth of Yang [or the sun]." What is interesting is that the ancient civilizations of the West began the new year at the vernal equinox, but the ancient Chinese started counting the new year from the winter solstice.
From this perspective, there is no reason to fear the fact that the sun's influence is remotely transmitted, and the influence of its relative position upon the earth is delayed by a month. There is no need to fear the Lesser Cold and Great Cold which follow at the heels of the winter solstice. Once the Yang energy is born, we might as well patiently wait for the warmth of spring and the blossoming of flowers. Indeed, the simple and naive cosmology of the ancient Chinese contains profound meaning.
[Picture Caption]
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In agrarian society, which depends on the natural elements for its sustenance, the 24 Solar Terms are the foundation of farming activities. This picture, commemorating the Chinese New Year, depicts the custom of "beating the spring cow" at the Commencement of Spring.
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The 24 Solar Terms Fixed Along the Earth's Orbital Plane
(Data courtesy of Liu Chao-min, Civil Aeronautics Administration Meteorological Center)
(Drawing by Lee Su-ling)
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The beginning of June falls right in the middle of the Solar Terms "Little Fullness" and "Husks of Grain"; the annual harvest of wheat in northern China has already grown sturdy and ample. The photo was taken in mainland China's Shandong Province.
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The shed cicada shell is a symbol of the arrival of summer in Taiwan.
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ROC 1994 Seasonal Calendar
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In the middle of July, after the first crop of rice is harvested, farmers can only take a short breather, before they start in on the second crop of rice. (Sinorama file photo)
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Black mullet is the treasure of Taiwan's fisheries industry. All the fishing folk of Kaohsiung know that the period for harvesting mullet roe is only ten-odd days long, falling at the time of the winter solstice. If they can manage a bountiful harvest, they can enjoy a good winter.