What is the meaning of "summer connection" in the poem "Spring rain shakes the spring and the valley days, and summer is full and summer is summer connection"?

1. The "summer fever" in the poem "Spring rains startle the spring and clear the valley, summer is full and summer is hot" refers to two solar terms: little summer and big company.

Second, the source

"Spring rains shake the spring and clear the valley, summer is full and summer is hot" comes from modern Li Qiulin and solar term song. The original song is "Spring rain surprises spring and bright valley days, summer is full and summer is hot, autumn dew is frosty, and there is Melissa Zhou in winter." This song is compiled according to the law of names for the convenience of memory. The first four sentences are composed of one word in each solar term in sequence, which is the main body of the whole solar term song, and the last four sentences are the time laws of the 24 solar terms.

Three or twenty-four solar terms

Twenty-four solar terms are a kind of experience accumulation and wisdom crystallization that China summed up in ancient times to guide farming, and they are gorgeous treasures of China classical culture.

The 24 solar terms are called beginning of spring, Rain, Sting, Vernal Equinox, Qingming, Grain Rain, Changxia, Xiaoman, Mangzhong, Summer Solstice, Xiaoshu, beginning of autumn, Chushu, Bailu, Autumnal Equinox, Cold Dew, Chufrost, beginning of winter, Light Snow, Heavy Snow, Winter Solstice, Slight Cold and Severe Cold.

The 24 solar terms are evenly distributed in a year, and there are only six solar terms in each season.

Extended data

The origin of the twenty-four solar terms

Twenty-four solar terms originated in the Yellow River valley in the pre-Qin period and are the crystallization of long-term experience and wisdom of working people in ancient China. Our ancestors called five days 1, and three days were called solar terms. The whole year was divided into 72 days out of 24 solar terms.

As early as the Spring and Autumn Period and the Warring States Period, the sundial was measured by earth gauge in ancient China (that is, a pole was erected on the plane to measure the length of the midday sun shadow) to determine the four solar terms: vernal equinox, summer solstice, autumnal equinox and winter solstice.

In a year, the shortest day of the shadow of returning to the earth at noon is the summer solstice, the longest day is the winter solstice, and the shadow with moderate length is the vernal equinox or autumnal equinox. After continuous improvement and perfection, by the Qin and Han Dynasties, the 24 solar terms had been completely established.

Twenty-four solar terms are based on the position of the earth on the ecliptic, reflecting the regression movement of the earth and the changes in cold and hot seasons.

In BC 104, the taichu calendar written by Deng Ping officially set 24 solar terms in the calendar, and defined the astronomical position of the 24 solar terms.