How to calculate the delay?

The entry time is different from year to year, and it will be officially entered at 0: 00 on July 16, 2022.

In 2022, after the solar term of the summer solstice, the summer solstice will be June 2 1, and July 16 will be the first day of setting. It is divided into three stages: the beginning, the middle and the end. Generally, mid-July to mid-August is the hottest time of the year. The length of accommodation in dog days is not fixed every year, and the length of accommodation is also different.

The dog days include "the beginning, the middle and the end", in which the beginning and the end are 65,438+00 days, and the number of days in the middle is long or short, which may be 65,438+00 days or 20 days. If there are four shifts between the summer solstice and the beginning of autumn, there will be 65,438+00 days in the middle, and if there are five shifts between the summer solstice and the beginning of autumn. Therefore, the whole dog days will last either 30 days or 40 days.