The vernal equinox is one of the solar terms reflecting the changes of the four seasons, and it is also the fourth of the 24 solar terms. In ancient China, beginning of spring, Changxia, beginning of autumn and beginning of winter were used to indicate the beginning of the four seasons. The vernal equinox, summer solstice, autumn equinox and winter solstice are in the middle of each season.
On the vernal equinox, the sun shines directly on the equator, and the time between day and night is equal all over the earth. Therefore, the ancient vernal equinox and autumnal equinox are also called "equinox", and there is a folk proverb that "vernal equinox and autumnal equinox are equally divided day and night".
During the vernal equinox, yin and yang in nature account for half, so the principle of balance between yin and yang should be followed in daily diet to maintain the balance, coordination and stability of body functions.
In addition, the climate in the vernal equinox season is very suitable for the reproduction and spread of various germs. It is very beneficial to human health and psychological adjustment to open doors and windows frequently to ventilate the house and plant some flowers and plants in the house to improve air quality and negative ion concentration.