What is Geng Day? How many days is a Geng Day?

Gengri is a noun used to record time. A Geng day is ten days.

In ancient China, time was recorded through the combination of heavenly stems and earthly branches. The number of heavenly stems is 65,438+00, namely, A, B, C, D, E, G, Xin, Ren and Gui, so there is a Geng Day every 65,438+00 days.

"The third watch" refers to the three characters of "Geng" from the summer solstice, the third watch is the first day of lodging, the fourth watch is the first day of lodging, and the first watch after beginning of autumn is the first day of lodging for the last time. The first day and the last day are 10, and the days in between are not fixed. There are four Geng days between the summer solstice and beginning of autumn, with an average of 10 days; There are five Geng days with an average of 20 days.

Extended data

365 days a year (366 days in leap year) is not an integer multiple of 10. One day this year is Geng Day, and next year is not necessarily Geng Day. Due to the uncertainty of Geng day, the date of entering the cave is different every year.

The dog days are the hottest days of the year. "V" means being forced to hide underground. "Three volts" is the general name of the initial, middle and final volts, which appears from mid-July to mid-August in the solar calendar every year.

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