The weather in March and June

"Dog days" means that the third Geng day (June 2 1 or 22 in the solar calendar) from summer to the future is the first day (with ten days), the fourth Geng day is the middle day (with ten days in some years and twenty days in some years), and the first Geng day (August 7 or 8 in the solar calendar) after beginning of autumn is the third day (with ten days). In this way, the dog has a fixed day. According to this regulation, it can be inferred that the dog days are from mid-July to mid-August in the solar calendar.

"March 9th" refers to the third "nine days" after the winter solstice, that is, the 19th to 27th days after the winter solstice. There is a saying "Jiujiu" in the China lunar calendar, which is used to calculate the seasons. The calculation method is from the solstice of winter (counting from the solstice of winter, which means the beginning of cold), every nine days are called a nine, the first nine days are called a nine, the second nine days are called a 29, and so on until the ninth nine days, when the number reaches 998 1 day. At this time, winter has passed and spring has arrived.

Generally, it is the coldest in "Sanjiu".

"Three days in long summer and three days in beginning of winter" means that no matter how cold and hot the weather is, we should persist in physical exercise, so that our body can better acquire the ability to keep pace with the four seasons and adapt to the cold and summer. In fact, in the hot summer, people who don't like physical exercise, the more afraid of heat, the more hot they feel, the less active they are, and the worse their adaptability to the external environment. Exercising in a hot environment can dilate subcutaneous capillaries, accelerate the opening of body glands, improve heat dissipation ability, and make the body have a stronger ability to regulate body temperature, so many experts advocate "summer training in dog days".