The exact time to come out in 2023.

The year 2023 appeared on August 20th.

The summer solstice in 2023 is June 2 1, and that day is Geng Xuri. Therefore, it is time to enter the ambush after two days. The summer solstice is the first Geng day, counting from 10, the second Geng day is July 1 day (Geng Shen day), and then counting from 10, the third Geng day is July10/day (Geng Wu day

The dog days are divided into the beginning, the middle and the end, in which the beginning and the end are all 10 days (fixed time), so starting from August 10, counting back to 10 days is the last day of the whole day. After calculation, the next 10 day is August 19, which means that this day is the last day of the dog days.

After lodging, the surface humidity increases, and the heat absorbed every day is more, but the heat emitted is less, and the heat on the surface is accumulated. So it gets hotter every day, and when it enters the dog days, the accumulated heat on the ground reaches its peak and the weather is the hottest. In addition, there is much rain in summer, the air humidity is high, and the heat capacity of water is much greater than that of dry air, which is also an important reason for the sultry weather.

Dog days calculation:

The traditional almanac stipulates that "counting from the third Geng day in summer", that is to say, "counting down from the summer day until the third Geng day" is about to begin to dormant. The "Geng Day" here refers to the days prefixed with "Geng" in the ancient "Ganzhi Jiri Law". "crouching" means being forced to hide underground; This also means that it is too hot to move.

The length of dog days mainly lies in the difference between middle and next days. Because the third Geng day (the first autumn) after the summer solstice solar term occurs at different times every year, the number of days in the middle autumn is also different. The incubation time is long or short, which may be 10 day or 20 days. So some years dog days are 30 days, and some years are 40 days.