Does the "summer solstice" on the calendar mean the beginning or end of this solar term?

During the summer solstice, it means the official start of hot weather, and then the weather is getting hotter and sultry.

Solstice is the earliest of the 24 solar terms. In the 7th century BC, the shadow of the sun was measured by civil soil gauge, thus the summer solstice was determined. The annual summer solstice begins on June 2nd1day (or 22nd) and ends on July 7th (or 8th). According to "Zunxian Manuscript", "The sun arrives in the north, the days are long and the shadows are short, so it is called the summer solstice. At best, it is excellent. " On the day of summer solstice, the sun directly reaches the northernmost part of the year, almost directly to the Tropic of Cancer (23 26' north latitude), and the daytime in the northern hemisphere is the longest, and the farther north it is, the longer it is. For example, the daily length of Haikou in Hainan is a little more than 13 hours, Hangzhou is 14 hours, Beijing is about 15 hours, and Mohe in Heilongjiang can reach 17 hours. From summer to the future, the position of direct sunlight on the ground gradually moves southward, and the daytime in the northern hemisphere is shortened day by day. There is a folk proverb that "eating noodles on the solstice in summer will shorten the day". At this time, the southern hemisphere is in the middle of winter.

In ancient China, the summer solstice was divided into three phases: "the first phase of antlers decomposition; Second, wait for cicadas to start singing; Third-class Pinellia ternata. " Although Mi and Lu belong to the same family, the ancients thought they belonged to Yin and Yang. The deer's horn faces forward, so it belongs to Yang. On the solstice of summer, Yin Qi was born, and Yang Qi began to decline, so the front antlers began to fall off. Because mi belongs to yin, it falls in the corner of winter; After the solstice of summer, the male cicada fluttered and sang because of Yin Qi's feeling; Pinellia ternata is a shade-loving herb, named after it was born in swamps or paddy fields in midsummer. It can be seen that in the hot summer, some yin-loving creatures began to appear, while positive creatures began to decline.