The agency began to calculate from that day.

The calculation of dog days is based on solar terms and branch dates.

The specific method is: the third Geng Day is the first day after long summer's arrival. This year's summer solstice is 6/2 1, which is Bingzi Day, the third Geng Day is 7/ 15, and the fourth Geng Day is 7/25, which is the first day after beginning of autumn.

From the first rainy day to the last rainy day, it is usually 30 days, while the rainy day is 40 days. (This year is it)

There are other years, such as 199 1, 7/ 19, 7/29, 8/8. The dog days are 30 days.

Record the Book of Yin and Yang;

After the summer solstice, the third night is the beginning, the fourth is the middle, and beginning of autumn is the end.