The vernal equinox is spring, and the next couplet is sought before and after the vernal equinox.

The vernal equinox is spring, and the next couplet is sought before and after the vernal equinox.

I said:

The first part: spring equinox, before and after the vernal equinox;

The bottom line is: summer solstice in Zhixia, summer solstice in Yin and Yang division.

Explanation: The summer solstice in Zhixia means that the daytime is the longest in all parts of the northern hemisphere. The yin and yang of the summer solstice means that the summer solstice is the turning point of the sun. After the arrival of the summer solstice, the stars in the night sky gradually become summer stars.

Summer solstice is one of the 24 solar terms, which occurs on June 2 1 or 22 of the Gregorian calendar every year. On the day of summer solstice, the sun moves to 90 degrees of the yellow meridian (summer solstice, currently in Gemini), and the position where the sun directly hits the ground reaches the northernmost point of the year, almost directly to the Tropic of Cancer. At this time, the daylight hours in all parts of the northern hemisphere reach the longest in the whole year. For the Tropic of Cancer and its northern area, the summer solstice is also the highest day of the year at noon. During the summer solstice in Beijing, the daytime can be as long as 15 hours, and the height of the sun is as high as 73 32' at noon. On this day, the northern hemisphere received the most solar radiation, almost twice as much as the southern hemisphere.

Astronomical experts say that the solstice in summer is the turning point of the sun. After this day, I went back. The direct sunlight point moved southward from the Tropic of Cancer, and the daylight in the northern hemisphere became shorter and shorter day by day. After the summer solstice, the Tropic of Cancer and its northern region, the midday sun altitude angle also began to decrease. At the same time, after the arrival of the summer solstice, the stars in the night sky gradually became summer stars.