The Vernal Equinox is one of the twenty-four solar terms and the fourth solar term in spring. On this day, Chinese folk have customs such as flying kites, eating spring vegetables, and setting eggs. As for why eggs are set on the Spring Equinox? The reasons are as follows:

According to historical records, the tradition of setting eggs on the spring equinox originated in China in 4000 years ago. It was originally to celebrate the coming of spring. Therefore, egg erecting has nothing to do with the vernal equinox, but the center of gravity of the egg must be lower than the curve of the maximum circumference in the middle of the egg. According to ancient legends, it is easiest to stand eggs on the vernal equinox. Over time, it has become a tradition to stand eggs on the vernal equinox.

The reason why eggs can be laid on the Spring Equinox is that the sun shines directly on the equator. Day and night are equal in the northern and southern hemispheres, which means that day and night are equally divided into twelve hours each. The proverb says, "Eat the food of the Spring Equinox, and the day will grow by a thread." The axis of the earth's north and south poles and the earth's orbit around the sun are in a state of relative balance of forces, and the gravity of the earth is stable. Therefore, only the vernal equinox is the best time for eggs to stand upright without falling over. For children, the process of setting eggs is also a good time to cultivate patience, calmness, and concentration. Although there are wins and losses, it just adds some laughter. Adults also take the opportunity to educate and encourage them, which is also entertaining and educational.