What time does 202 1 enter the volt?

2021July 1 1 entered the volt at 0: 00.

Entering volts means entering "three volts". There is a folk proverb, "The first night falls in summer", which is the basis for establishing the first autumn. The almanac stipulates that "the number of volts starts from the third day of summer", that is to say, "it starts to count down from summer" and begins to fall on the third "Geng Day". The "Geng Day" here refers to the days prefixed with "Geng" in the ancient "Ganzhi Jiri Law".

The so-called heat is in volts, which can be divided into initial, middle and final volts, and its date is determined by the date when the solar terms cooperate with the main branch year. The climate in dog days is characterized by high temperature and high humidity, because the southeast wind blows in dog days, and the air is humid. The humidity of the wind causes great humidity in dog days.

Date calculation:

In ancient China, time was recorded by combining heavenly stems and earthly branches. The number of heavenly stems is 10, which is A, B, C, D, E, Ji, G, Xin, Ren and Gui, and the number of earthly branches is 12, which is Zi, Ugly, Yin, Mao, Chen, Si, Wu, Wei, Shen, You and Yi. Heavenly stems and earthly branches, Jia Zi, Yi Chou, Bing Yin, Ding Mao. Cross-match 60 times, so it is called 60 flowers.

"Three Geng" means meeting three "Geng" characters, and the third Geng Day will be the first time. Because the number of heavenly stems is 10, there is a Geng Day every 10 day, such as Geng Zi Day, Geng Yin Day and Chen Geng Day. 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 accommodation is different every year.