What does "v" mean?

Futian; Folli. Refers to the summer to the day before the third Geng day in the future to the second Geng day after beginning of autumn, which is divided into the first, middle and last days, collectively referred to as the three days, which is equivalent to the middle of July to the end of August in the solar calendar [three days; Hot season]

Fu is the five elements' view of seasons: originally, the four seasons were wood, fire, gold and water. Wood makes a fire, and fire makes gold. If there is a fire, I dare not come out in autumn. Latency is necessary. Scholars of the five elements call this period "Fu", also called "Long Summer", and the five elements are "Earth", and one year is five seasons. In this way, wood, fire, earth, gold and water are related. Because autumn belongs to "Geng Xin Gold", it is counted from "Geng Day". Since the hottest time starts from summer to 20-30 days in the future, lodging starts from summer to the third watch in the future. Because there is a big difference in the time from Geng Day to summer solstice, there are 40 days of "volt" and 30 days of "volt". Generally, there is a "V" behind beginning of autumn, which is the basic law.