Four seas network: every summer, there will be three dog days, sometimes there will even be leap mid volt, mid volt is the hottest of the three dog days, so do you have leap mid volt in 2018? Why leap mid volt?
Sanfu is the hottest 30 or 40 days of the year in Central China. Sanfu is calculated according to the lunar calendar, which is between the late July and the early August of the lunar calendar. The time of ambush is not fixed every year, and the length of the ambush is not the same. It needs to be calculated by consulting books. Simply, the four word formula of 'summer solstice three Geng' can be used to express the date of ambush, that is, from the third 'Geng' day after the summer solstice, the first ambush is 10 days, the middle ambush is 10 days or 20 days, and the last ambush is 10 days.
In ancient China, the 'ganzhiji Japanese method' was popular. 60 groups of names, which were matched by 10 heavenly stems and 12 earthly branches, were used to record the dates and circulate them. Every day when there is the word "Geng", it is called "Geng day". The word "Geng" of Geng day is the seventh of the ten Heavenly Stems of "a, B, C, D, e, I, G, Xin, Ren, GUI". Geng day is repeated every 10 days.
From the beginning of the summer solstice, according to the arrangement of the days of the GaN and Zhi dynasties, the third day of Geng is the first day of ambush, the fourth day of Geng is the middle day of ambush, and the first day of Geng after the beginning of autumn is the last day of ambush. When there are 4 g days between the summer solstice and the beginning of autumn, the median period is 10 days, and 5 g days is 20 days. It seems that the occurrence of the day of Geng will affect the length of the middle volt, so there are some years with 30 days of dog days and some years with 40 days of dog days.
Is there a leap in 2018
Yes, there are two MV in 2018, i.e. run MV. The MV in 2018 has 20 days.
Zhongfu is from the fourth day after the summer solstice to the day before the first day after the beginning of autumn. According to the regulations, the third day of the third prostration is the first day of the first prostration, the first day of the first prostration is the first day of the last prostration, and the second day of the second prostration is the end of the prostration.
Why is there a leap in the middle
The occurrence of intercalated Zhongfu is related to the Geng day after the summer solstice, and the occurrence of Geng day will affect the length of Zhongfu. Because when there are 4 g days between the summer solstice and the beginning of autumn, the average period is 10 days, and when there are 5 g days, it is 20 days. Intercalation is not an annual occurrence.
From the beginning of the summer solstice, according to the arrangement of the days of the GaN and Zhi dynasties, the third day of Geng is the first day of ambush, the fourth day of Geng is the middle day of ambush, and the first day of Geng after the beginning of autumn is the last day of ambush. Every Geng day is separated by 10 days, the time from the first to the middle is 10 days, and the last is 10 days; the middle may be 10 days, or 20 days.
The dog days in 2018
The dog days in 2018 are 40 days in total
July 17, 2018 - July 26, 2018, the first fall, 10 days
July 27, 2018 - August 15, 2018, the first fall, 20 days
August 16, 2018 - August 25, 2018, the first fall, 10 days