As soon as the summer solstice passes, the Yin Qi kicks in, and the days gradually become shorter.

Extended information:

The summer solstice falls on June 20, 21, or 22 of the Gregorian calendar every year. The summer solstice is the earliest identified solar term among the twenty-four solar terms. In the seventh century BC, ancestors used Tugui's method of measuring the sun's shadow to determine the time of the summer solstice. According to the "Kezunxiandu Manuscript": "When the sun reaches the north, the sun is long and the shadow is short, so it is called the summer solstice. The solstice is the extreme."

So on the day of the summer solstice , the position where the sun shines directly on the ground will reach the northern end of the year, almost directly hitting the Tropic of Cancer (23°26' north latitude). Therefore, the summer solstice is the longest day of the year in all parts of the northern hemisphere. In the Beijing area, the height of the sun at noon on the summer solstice is as high as 73°32′.

Chinese people divide the 15 days after the summer solstice into three "hours", usually 3 days in the first hour, 5 days in the middle, and 7 days in the last hour. During this period, most areas of our country have higher temperatures and sufficient sunshine. Crops grow quickly and require relatively large amounts of water. Therefore, the amount of precipitation at this time has a great impact on crops, so there is a saying that "summer solstice raindrops are worth a thousand pieces of gold".

As an important solar term, the summer solstice has a long history. The origin of the summer solstice is related to ancient Chinese farming culture. In ancient times, the summer solstice was the time when farmers were busy working in the fields, and it was also the time when crops grew most vigorously. Therefore, people hold a series of celebrations on the summer solstice to pray for a good harvest and blessings.

The Summer Solstice has rich allusions in Chinese culture. One of the most famous allusions is the legend about Fuxi. According to legend, Fuxi was a mythical figure in ancient China who created the Bagua on the day of the summer solstice, which provided the basis for divination and predictions in later generations.

The Summer Solstice not only plays an important role in China, but also has similar celebrations in other Asian countries and regions. For example, Japan's Summer Solstice Festival is called "Dragon Boat Festival" and has similar customs to China's Dragon Boat Festival, such as eating rice dumplings and holding dragon boat races. In addition, the summer solstice is also the time when some Western countries hold summer carnivals and music festivals, where people welcome the arrival of summer through music, dance and celebrations.