Vernal Equinox or Spring Equinox is the fourth solar terms in the total twenty - four . It ' s the middle of spring and usually on the 20 or 21 of March every year .
On this day , the sun directly blazes down the equator , so that day and night is equal in length .
Because it ' s the middle of spring , the weather is so comfortable and the scenery is beautiful that people are likely to go out for a hiking . It ' s also a good time for crop growing , so the farmers acre often busy in this period .