What do you mean by three volts and three nines?

1, three volts, which is the general name of the first, middle and last volts, is the hottest season in a year. The dog days appear in the Gregorian calendar from mid-July to mid-August every year, and its climatic characteristics are high temperature, low pressure, high humidity and low wind speed. "V" means being forced to hide underground. Three volts can be divided into initial volts, intermediate volts and final volts, and their dates are determined by the coordination of solar terms and solar terms in the dry branch calendar.

2. Sanjiu is the third nine days from winter to the future, which is about the middle and late period of 1. Dog days are the day before the third Geng Day from summer to the future and the second Geng Day after beginning of autumn, that is, from mid-July to mid-August. "March 9th" refers to the third "nine days" after the winter solstice, that is, the 19th to 27th days after the winter solstice. "The third nine days after the winter solstice" refers to "March 99", which is also the day when March 99 and April 99 intersect, not "March 99", that is, "March 99" is nine days instead of one day. People say, "it's cold for nine, and it's cold for nine in March." "March 9th" generally appears in the winter from solstice to shock.