What is the vernal equinox?

The vernal equinox is one of the 24 solar terms and the fourth solar term in spring.

Historical origin:

1, meaning of the festival name: "vernal equinox" means half, divided into two parts, equal day and night, and the cold and summer are balanced. In addition, the vernal equinox also means sharing spring equally. Traditionally, it is spring from beginning of spring to long summer, and the vernal equinox is in the middle of three months in spring. Therefore, the vernal equinox was also called "Japan-China", "Day and Night Equinox" and "Midspring Moon" in ancient times.

2. Spread of solar terms: "Twenty-four solar terms" is the product of ancient farming civilization in China, which is related to the time when officials raised gossip and has a long history. In the process of cultural exchange and communication of historical development, four solar terms (vernal equinox, autumnal equinox, summer solstice, winter solstice) of China's "twenty-four solar terms" reflecting the return movement of the direct point of the sun spread throughout the pre-Qin period.

Astronomical phenomena:

At the vernal equinox, the bucket handle of the Big Dipper points due east, and the sun reaches 0 degrees of the yellow meridian. The festival will be held on March 20th or March 2nd1day of the Gregorian calendar. The vernal equinox solar term usually refers to a certain period of time, that is, the sun is located between 0 degrees and 15 degrees of the yellow meridian, from March 20 to April 5 of the Gregorian calendar. In ancient times, the vernal equinox was also called "Japan-China", "Day and Night Equinox" and "Midspring Moon". Because the sun shines directly on the equator on this day, the days in the northern hemisphere and the southern hemisphere are as long as the nights.