The vernal equinox is one of the 24 solar terms and the fourth solar term in spring. Douzhiren, with a solar yellow longitude of 0 °, meets on March 19-22 of the Gregorian calendar every year.

The vernal equinox is of great significance in astronomy. On the day of the vernal equinox, the day and night in the northern and southern hemispheres are divided equally. Since then, the direct sunlight position has continued to shift from the equator to the northern hemisphere, and the days in various parts of the northern hemisphere have begun to lengthen compared to the nights in the southern hemisphere.

In terms of climate, there are also relatively obvious characteristics. Except for the Qinghai-Tibet Plateau, Northeast China, Northwest China, and the northern part of North China, China has entered a beautiful spring.

The meaning of the vernal equinox is that the time of the day is divided equally between day and night, with 12 hours each; The second is that in ancient times, from the beginning of spring to the beginning of summer, the spring equinox was among the three months of spring, which divided the spring equally.

After the spring equinox, the climate is mild, with abundant rain and bright sunshine. During the Spring Equinox season, Chinese folk have customs such as flying kites, eating spring vegetables, and laying eggs.