Rain: The rain begins and increases gradually.
Sting: Sting means hiding. Sting refers to the sudden movement of spring thunder, which awakens the animals dormant in the soil and hibernating.
Equinox: Equinox means equal share. The vernal equinox means that day and night are equally divided.
Qingming: It's sunny and lush.
Grain Rain: Rain makes a hundred valleys. With sufficient and timely rainfall, cereal crops can thrive.
Long summer: The beginning of summer.
Xiaoman: The seeds of summer crops such as wheat are full.
Miscanthus species: awned crops such as wheat are mature.
Summer Solstice: The hot summer is coming.
Summer heat: Summer heat means heat. A slight summer heat is when the climate starts to get hot.
Big agency: the hottest time of the year.
Beginning of autumn: The beginning of autumn.
Summer heat: place means to stop and hide. Summer is the end of a hot summer day.
White dew: The weather turns cold, and the dew is condensed and white.
Autumnal equinox: divided equally between day and night.
Cold dew: dew is cold and will freeze.
First frost: It's getting colder and frosty.
Beginning of winter: The beginning of winter.
Xiaoxue: It began to snow.
Heavy snow: the snowfall is increasing, and there may be snow on the ground.
Winter Solstice: The cold winter is coming.
Slight cold: The climate began to get cold.
Great cold: the coldest time of the year.
First, the name of 24 solar terms is divided into four groups according to the sequence, and each group is divided into two halves:
Beginning of spring, rain, fright, vernal equinox, Qingming, Grain Rain;
Long summer, Xiaoman, Mangzhong, Summer Solstice, Xiaoshu, Dashu;
Beginning of autumn, Chu Shu, Bailu, Autumnal Equinox, Cold Dew, first frost;
Beginning of winter, light snow, heavy snow. Winter solstice, slight cold, severe cold.
As soon as this is put out, you can immediately see that after the first four characters are set up, the second half begins, and then the four characters "Spring, Summer, Autumn and Winter" lead. What does this mean? It goes without saying that the four seasons of spring, summer, autumn and winter stand up from four, and standing up is the beginning. The second half of "spring, summer, autumn and winter" is accompanied by two words "fen" and two words "zhi". What do you mean by points? The simplest "split" is "split in two", which means that the season is split in two here. What about the other two words "zhi"? It is easy to misunderstand the meaning of "the end", but what is the end? Don't think it's the end of the season, but the sun has gone north or south and is going back. If the original meaning of the word "zhi" is exactly investigated, "zhi" means extreme. For example, when we say "at least", that is to say, it can't be less, it's extremely small. The summer solstice means that the sun has gone north to the extreme and will turn back, but the summer is not over, but just at the midpoint. The winter solstice is similar. The sun has just reached the extreme south point and started to turn to the north. Winter is halfway through.
These eight solar terms are usually called four seasons and eight festivals. Actually, it's four beginnings and eight middle schools. They define the four seasons. But what do the four seasons mean? Isn't it hot in summer? Isn't it cold in winter? Why is it that it's not until the end of summer that it gets hot, and it's not until the end of winter that it gets cold? Isn't this summer and winter crooked?
This question really makes sense. Did the ancients set the four seasons wrong? Only by thinking deeply can we understand the mystery.
It turns out that although cold and heat depend on the irradiation of the sun, the reasons why people feel cold and heat are very complicated, and the sun is not the decisive factor. For example, a big house has two doors at both ends. In winter, a pot of fire enters from the left door, moves slowly to the right door, and finally exits from the right door. Do you think it's the temperature in the house when the fire moves to the center? I'm sure you said no, it was the temperature when the fire moved to the right door. The reason is that it takes time for the fire to dissipate heat into the air, and when the fire moves to the middle, the heat has not yet dispersed. Sun exposure is similar, and the factors affecting temperature are much more complicated. Therefore, the concept of season, when it first happened, was very simple, according to people's direct feelings. When people want to define the accurate concept of the four seasons and want to incorporate the concept of the four seasons into the calendar, people realize that they can't define the four seasons just according to the temperature. At the same time, the temperature varies from place to place, and the temperature is not always the same in the same duration in different years. Therefore, we must find the most stable and universally applicable standard for determining the four seasons. Our clever ancestors found this standard, that is, the north-south position of the sun. This standard is astronomical. Although the north-south position of the sun cannot determine the temperature of a place, it can generally affect the temperature change in a year at a regular rate. Therefore, it is of practical value to determine the four seasons according to the north-south position of the sun. Of course, the four seasons determined in this way must be different from the direct seasons determined by temperature. Usually, the direct seasons are called meteorological seasons. Meteorological seasons cannot be used as calendar seasons. The astronomical seasons mentioned just now can be used as calendar seasons. Meteorological seasons usually lag behind astronomical seasons, and the Yellow River Basin in China lags behind by about three periods. The four seasons set by the above eight in 24 solar terms are the astronomical seasons and the calendar seasons. This can explain why the great heat and cold are not in the middle of summer and winter.
The four seasons and eight festivals are the skeleton of 24 solar terms and the calendar. The other 16 solar terms are branches or meat on the skeleton. The use of branches or meat is a bridge between astronomical seasons and meteorological seasons.
We see "rain" and "fright" inserted in the bisection between beginning of spring and the vernal equinox. These two names describe the meteorological or biological characteristics of the first half of spring. It's going to rain, and the little life hiding in the ground for the winter will start to wake up when it hears the call of the sun. Between the vernal equinox and long summer are "Qingming" and "Grain Rain". From the "rainy season", we can know the climate in Tomb-Sweeping Day. Literally, we can know from Grain Rain that this is the season when crops need rain to promote growth. Insert "Xiaoman" and "Mangzhong" between long summer and the Summer Solstice. When Xiaoman is filled with wheat, awn seed is a busy season for wheat harvest and autumn planting. Between the summer solstice and beginning of autumn, there are "light heat" and "great heat", which is the hottest month. Between beginning of autumn and the autumnal equinox, the words "summer heat" and "white dew" are inserted, which is the end of summer heat and the early autumn season when dew begins to appear sooner or later. The meaning of inserting "cold dew" and "first frost" between the autumnal equinox and beginning of winter is self-evident. Insert "light snow" and "heavy snow" between beginning of winter and the winter solstice; The meteorological significance of inserting "slight cold" and "severe cold" between the winter solstice and beginning of spring is more clear, so it is unnecessary to explain. In a word, the sixteen solar terms inserted between the eight sections are used to describe the meteorology and phenology of the Yellow River Basin in China. Any other part of the world can imitate and give appropriate names to these sixteen solar terms according to the meteorological and phenological characteristics of each place, just like the relationship between world time and zone. So: 24 solar terms is actually applicable all over the world.
After understanding the astronomical significance of 24 solar terms, we will know how important it is for the calendar to take 24 solar terms as the criterion. However, 24 solar terms is defined by the 24 equal angles of the great circle that the sun passes through in the sky, not by the 24 equal times of a year, so the time interval is not equal. According to the approximate number of days, some are approximately 15 days, and some are approximately 16 days. Therefore, how to divide the months of a year in order to express 24 solar terms concisely and accurately enough, so that they can be arranged with the simplest rules and easily memorized, is an important task in calendar design.