When to ambush?

Sanfu "starts from the summer solstice (June 21 or 22 in the Gregorian calendar). The first day after the beginning of autumn (August 7 or 8 in the Gregorian calendar) is Sanfu (ten days), and the fourth day is Zhongfu. According to this rule, it can be calculated that the period of Dog Day is from mid-July to mid-August in the Gregorian calendar. >

"Sanjiu" refers to the third "nine days" after the winter solstice, that is, the 19th to the 27th day after the winter solstice. The Chinese lunar calendar has a saying of "September 9th", which is used for calculation. Season. The calculation method is from the winter solstice in winter (counting from the winter solstice, called "Jiaojiu", which means the beginning of cold), every nine days is a "nine", the first nine days are called "nine", and the last nine days are called "jiu" "Twenty-nine", and so on, until the ninth nine days, that is, the ninth nine days, totaling nine hundred and eighty-one days. At this time, winter has passed and spring has come.

Generally September No. 9 is the coldest day.

"Three days in summer and three days in winter" means that no matter how cold or hot the weather is, you must keep exercising so that you can better "keep up with the four seasons and adapt to the cold and heat." In fact, in hot summer, people who do not like physical exercise are more afraid of heat, feel hotter, and less active, and their ability to adapt to the external environment will be worse. The telangiectasia accelerates the opening of the body's glands, improves heat dissipation, and gives the body a stronger ability to regulate body temperature. Therefore, many experts advocate "three days of exercise in summer."