When the mysterious bird arrived, Renai made a sound. What is the solar term when electricity starts?

It is the vernal equinox, and the corresponding phenological phenomenon in the ancient Yellow River basin is "the arrival of a mysterious bird, a thunder, and the beginning of electricity" (see Nong Sang Tong Zhi). At this time, the overwintering crops in most parts of China entered the spring growth stage. A farmer's proverb in central China says, "Wheat rises at the vernal equinox, which is a worthwhile moment." The vernal equinox is also a traditional festival. In the Zhou dynasty, there was a ceremony to worship the sun at the vernal equinox.