The origin of vernal equinox language under the national flag of kindergarten

In ancient times, the vernal equinox was also called Japan-China, Day and Night Equinox and Midspring Moon. Because the vernal equinox is just in the middle of spring, it divides spring equally, so it is called vernal equinox. Dong Zhongshu of the Han Dynasty wrote in the Spring and Autumn Story, Up and Down of Yin and Yang: "As for the mid-spring moon, the yang is in the east and the yin is in the west, which is called the vernal equinox. The vernal equinox is half yin and half yang, so it is cold and summer day and night. " It is also mentioned in the 24 solar terms: "In mid-February, it is divided into half days, which means 90 days and a half, so it is called minutes. Autumn is synonymous. " Many ancient poems are related to the vernal equinox, such as Ugly Snow after the Vernal Equinox by Su Shi, Walking on the Sand by Ouyang Xiu and Vernal Equinox Day by Xu Xuan.