When did dog days start?

Dog days occur between the summer and the beginning of autumn, the hottest time of the year.

Dog days begin on the third Geng day after the summer solstice.

It is divided into the beginning, middle, and end, and lasts for 30 or 40 days in total. Not only is the number of days uncertain, but even the date on which the volts start varies from year to year.

In order to accurately count the Futian, it is necessary to understand the summer solstice day and the Ganzhi Chronology method. In fact, the date of the beginning of the number of volts is not based on a fixed date in the Gregorian calendar or lunar calendar, but is calculated by the Ganzhi date method.

The summer solstice is the 10th of the 24 solar terms, and the time point is between June 21 and 22 of the Gregorian calendar every year. The sun shines directly on the Tropic of Cancer and is the longest day of the year in the Northern Hemisphere. Shortly after the summer solstice, it is Futian.

As the saying goes: "On the summer solstice, three Geng will count the volts." The word "Geng" refers to the Geng in the heavenly stem. The meaning of this sentence is that the third Geng day after the summer solstice is the first day of the first volcane.

Dog days are counted from the third "Geng" day after the summer solstice. The initial period is 10 days, the middle period is 10 days or 20 days, and the terminal period is 10 days. When there are 4 Geng days between the summer solstice and the beginning of autumn, it is 10 days in the middle of the volt, and 20 days when there are 5 Geng days.

In ancient China, the "Stem Branch Chronology Method" was popular, and 60 different names were used to record the days with 10 heavenly stems and 12 earthly branches, and they were used in cycles. Every day with the word Geng is called Geng Day. Geng day is repeated every 10 days.

The dog days are calculated according to the lunar calendar, which is about the middle to late July of the solar calendar and the beginning of August. The time of the ambush is not fixed every year, and the length of the ambush is not the same, it is simple to use the "summer solstice three Geng" 4 words mantra to indicate the date of the ambush, and the morning and evening of the Geng day will affect the length of the ambush, so there are 30 days in some years, and 40 days in some years.

After the ambush, the surface humidity becomes larger, the heat absorbed every day is more, the heat emitted is less, and the heat of the surface layer accumulates, so it gets hotter and hotter day by day. In addition, there is a lot of 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 hot and humid weather. In July and August, the subtropical high strengthened, and under the control of the subtropical high, the downdraft inside the high pressure made the weather clear and cloudless, which was conducive to sunlight exposure, and the ground radiation warmed, and the weather became hotter.

Dog days generally begin in mid-July.

Dog days generally start in mid-July and end in late August. The time of the ambush is not fixed every year, and the length of the ambush is not the same, you need to check the almanac to calculate, and you can simply use the 4-word formula of "summer solstice three Geng" to indicate the date of ambush, that is, from the third "Geng" day after the summer solstice, the initial ambush is 10 days.

The time of ambush is not fixed every year, and the length of the ambush is also different, so it is necessary to check the almanac to calculate.

It is easy to use"Summer solstice three Geng"These 4-character mantras are used to indicate the date of the ambush, that is, from the third day after the summer solstice"G"The day is counted, and the first day is for.

10 days, 10 or 20 days for the middle volt, and 10 days for the last volt.

Dog days are the hottest and humid days of the year.

The so-called"Fu Tian'er", which refers to the lunar calendar"Dog days", which is the hottest time of the year.

It can be understood like this:"Volt"It's just that the weather is too hot, and it is not suitable to move. But dog days are called that"Volt", because there are also.

There are quite a few cold factors involved.

Dog days are the hottest of the year in the Central Plains.

Thirty or forty days, the dog days are calculated according to the lunar calendar, which is about the middle to late July of the solar calendar.

Until early August.