Why is the day and night of the autumn equinox different this year?

Because the sun is a sphere, not a point. If it is a point, the autumnal equinox season, day and night are equal in length. But because too far is not a point, the sunrise starts with a little bit of ethereal masculinity, and the sunset is completely timed by sunset, which leads to time error.

And sunrise and sunset are not the center of the sun, but the moment when the upper edge of the sun touches the horizon; Moreover, there is air refraction to be considered, which is influenced by many factors.

Extended data:

Climatic characteristics of autumnal equinox

According to the lunar calendar, "beginning of autumn" is the beginning of autumn and ends with "the first frost", and the "vernal equinox" is just half of the 90-day journey from beginning of autumn to the first frost. At the autumnal equinox, the Yangtze River basin and its vast northern area have entered autumn, and the daily average temperature has dropped below 22℃.

The cold air mass in the north began to have some influence. In most areas, the rainy season has just ended, with a cool breeze blowing gently, the sky is high and the clouds are light in Wan Liqing, the air is crisp in autumn, the sweet-scented osmanthus is fragrant, the crab is fat and the chrysanthemum is yellow, and the autumn equinox is a beautiful and pleasant season. It is also an important solar term in agricultural production. After the autumnal equinox, the direct point of the sun moved to the southern hemisphere, and the northern hemisphere got less and less solar radiation, while the ground lost more heat and the temperature dropped significantly.