When did Zhongfu appear?

V means hiding. According to historical records, "those who lie down avoid midsummer." "Three volts" refers to the initial, middle and final volts, that is, from mid-July to mid-August. The lunar calendar, founded in ancient China, used heavenly stems and earthly branches to arrange the year, month and day. Tiangan consists of ten words: A, B, C, D, E, G, Xin, Man and Ghost. According to the regulations, the third Geng day from the summer solstice is regarded as the 1 day of the first lodging, and the fourth Geng day is designated as the beginning day of intermediate lodging. The 1 th "Geng Day" from "beginning of autumn" is the start day of "late autumn", and the second Geng Day is designated as late autumn, that is, the dog days end. The third "Geng Day" after this year's "Summer" appeared on July 15, that is, it was a few volts, and entered the "middle volt" on July 25; The 1 th "Geng Day" after "beginning of autumn" is August14th, which is the last day. Therefore, this year's "mid-volt" has 20 days, and there are two kinds of "mid-volt" sayings among the people.