There are two solar terms, the day is as long as the night. Which solar term is it?

The two solar terms as long as day and night are the vernal equinox and the autumnal equinox.

The time between the vernal equinox and the autumnal equinox is about 182 and a half days. From the earth's orbit around the sun, it can be clearly seen that the vernal equinox is in the east and the autumnal equinox is in the west. The two solar terms set each other off and the two seasons are equal day and night. After the vernal equinox, the days gradually become longer until the summer solstice, and after the summer solstice, the days gradually become shorter, and by the autumn equinox, day and night become equal again.

The autumnal equinox has passed, and the night begins to lengthen slowly until the winter solstice, and then the night begins to shorten slowly from winter to the future. In the following year, the day and night time of the vernal equinox became equal again. This is a very interesting thing. It's interesting to think about the mutual care of the vernal equinox. Day and night are equally divided and the time is equal. The summer solstice is black and white, the summer solstice is white, the winter solstice is black, and there are endless changes throughout the year.

The difference between vernal equinox and autumnal equinox

1, the time is different: the vernal equinox is the fourth of the 24 solar terms, and it is celebrated every year on March 20th or March 2nd1day of the Gregorian calendar. The autumnal equinox is the sixteenth of the twenty-four solar terms, and the time is generally from September 22nd to September 24th in the Gregorian calendar every year.

2. The climate is different: the vernal equinox and the autumnal equinox are solar terms with special significance in spring and autumn. The vernal equinox represents the arrival of warmth and the autumnal equinox represents the arrival of cold. During the vernal equinox, the climate is mild, the rain is abundant and the sun is shining, and the wintering crops in most parts of China enter the spring growth stage. In the autumn equinox, most parts of China have entered a cool autumn with more rainfall and lower temperature.