Four seas network: three dog days is the hottest season of the year, ten days a volt, the temperature will remain high, three dog days in particular to pay attention to heatstroke prevention work, so how to calculate the three dog days? When and how many days does the dog days of 2017 start? Let's take a look at it together with Sihai Xiaobian!
The dog days in 2017 are 30 days from July 12
The first, middle and last three volts in 2017 are as follows, totaling 30 days
Early fall time in 2017: July 12, 2017 Gengchen
2017 Zhongfu time: July 22, 2017, Gengshu
Last time in 2017: August 11, 2017, Gengwu
The dog days in 2017 lasted for 30 days, from July 18 to August 17.
Date calculation method of three dog days
Three dog days, one volt is ten days, which is calculated according to the number of ten Heavenly stems. Therefore, it is divided into three rainy days, that is, the third dry day after the summer solstice is the first rainy day. For example, the summer solstice of 2006 is June 21 of the Western calendar year. The dry day of this day is Xinri. After 28 days, it is the third Geng day. Therefore, July 20 of 2006 is the beginning of the first volt. Ten days later, it is another Geng day, that is, July 30, it enters the second volt. Ten days later, it is another Geng day, and the first Geng day after the beginning of autumn, that is, August 9 In 2007, July 15 is the third day of Geng, which is the beginning of the first V (the first V); ten days later, it's another day of Geng, which is July 25, which is the second V (the second V); ten days later, it's another day of Geng, but it hasn't passed the beginning of autumn, and ten days later (there are 20 days in the second V), which is the first day of Geng, and it's the first day of Geng after the beginning of autumn August 14, that is, the third volt,. That is to say, it's very hot every year after entering the three dog days, especially the ten days (sometimes twenty days) in the middle dog days, which is the hottest. There is a saying among the people that "cold in September, hot in the middle".
The heart algorithm of the 21st century - Geng day formula: GR = (D - [y / 4]) mod 10 (GR Geng day, d even year 1 odd year 6, y year,  rounding, mod remainder)
For example, in 2006, GR = (1 - [6 / 4]) mod 10 = 0 (10), on July 20, 30, and 9.