Two volts or three volts?

The second volt is the hottest, followed by the first volt, and the third volt is cooler. "Three volts" is the general name of the first, middle and last three volts, and it is the hottest season in a year. The dog days appear in the solar calendar from mid-July to mid-August every year.

Climate characteristics in dog days: high temperature, low pressure, high humidity and low wind speed.

"Crouching" in "Dog Days" refers to Yin Qi being forced to hide underground by Yang Qi. After squatting, the ground humidity increases, the heat absorbed increases, and the heat emitted decreases, getting hotter every day.

The length of accommodation is not fixed every year, and the length of accommodation is also different. Generally, the head is 10 day, the third volt is 10 day, and the middle volt is 10 day or 20 days according to the almanac.