Dog days are the time when people should pay attention to healthy diet and summer vacation, but many people don't know how to determine the date of dog days and don't know the calculation formula of dog days? Here is how to determine the date of dog days and the calculation formula of dog days. How is the date of volt determined
According to the ancient Chinese calendar, the first day of the first fall is the third day after the summer solstice; The first day of the midsummer is the fourth day after the summer solstice; The first day of the last fall is the first Geng day after the beginning of autumn. Calculation formula of dog days
The traditional method of calculating the dog days is from the summer solstice, according to the arrangement of dry and branch days, and the third Geng day is the first one. The fourth Geng day is the middle fall, and the first Geng day after the beginning of autumn is the last fall.
Three dog days, one dog day is ten days, which is calculated according to the number of ten days. Therefore, it is divided into three dog days, that is, the Geng day on the third day after the summer solstice is the beginning day of the first dog day. For example, the summer solstice in 2006 is June 21 in the Western calendar year. The dry day on this day is Xin day. After 28 days, it is the third Geng day. Therefore, July 20 in 2006 is the beginning of the first volt; Ten days later, another Geng day, that is, July 30, entered the second volt; Ten days later, another Geng day, and the first Geng day after the beginning of autumn, that is, August 9, entered the third volt; If it is 2007, July 15 is the third Geng day, which is the beginning of the first volt (the first volt); Ten days later, another Geng day, that is, July 25, entered the second volt (medium volt); Ten days later, there is another Geng day, but before the beginning of autumn, there is another Geng day after ten days (there are 20 days in the middle of this year), and it is the first Geng day after the beginning of autumn, that is, on August 14, it enters the third volt,. That is to say, after the dog days every year, it is very hot, especially in the medium ten days (sometimes twenty days), which is the hottest. There is a folk saying that "cold is in March and September, and heat is in the middle".
21st century heart algorithm - Geng RI formula: GR = (D - [y / 4]) mod 10 (GR Geng RI, d even year 1 odd year 6, y year, [] rounding, mod remainder)
For example, in 2006, GR = (1 - [6 / 4]) mod 10 = 0 (10), initial voltage on July 20, intermediate voltage on August 30 and final voltage on August 9.