Which solar term is as long as day and night?

Vernal equinox: The vernal equinox is one of the 24 solar terms and the midpoint of 90 days in spring. The Gregorian calendar date is around March 21(20th to 22nd) every year.

In ancient times, the day when the sun reached the 0 (vernal equinox) longitude of the Yellow River was also called "Japan-China", "Day and Night" and "Midspring Moon". Twenty-four solar terms: "in mid-February, half a minute, that is, half of 90 days, so it is called minutes."

Autumn is synonymous. "Spring and Autumn Stories Yin and Yang in and out" said: "At the vernal equinox, Yin and Yang are also half-phase, so it is cold and hot day and night."

Autumnal Equinox: The 16th solar term among the 24 solar terms in the lunar calendar, usually on September 22nd or 23rd every year.

The climate in the south began to decline from this solar term. On this day, the sun reaches the longitude of 180 degrees, and points directly at the equator of the earth, so the day is divided into 24 hours, each with 12 hours; There is no extreme day and night phenomenon in the world.

After the autumnal equinox, the polar night range near the North Pole and the polar sun range near the South Pole gradually expanded. Twenty-four solar terms: "In mid-August, see the vernal equinox" and "the points are equal, which is 90 days and a half, so it is called points." Half a minute is the midpoint of ninety days in autumn.