A&B refers to which day of the lunar calendar?

A day and B day refer to 1 and 2 days of the lunar calendar.

According to heavenly stems and earthly branches, "A, B, C, D, E, Ji, G, Xin, Man and Ghost" is called ten days' work.

Each month is divided into three parts, 1- 10 days, 1 1-20 days and 2 1-30 days, with a period of ten days.

The days of 1- 10,1-20, and 2 1-30 are respectively: A day, B day, C day, D day, E day, Ji day, Geng day, Xin day, Ren day, and Geng day.

The ancients used heavenly stems and earthly branches to represent the date, date, month and year, that is, as a numerical serial number. Dry weather is the most common day. In Huangdi Neijing, when the disease gets better or worse, it is usually considered as a day, marked by heavenly dryness.

In the ancient calendar, there will be a record of what one day is heavenly stems and earthly branches, starting with A, the next day is B, and so on, and then behind the deck is A .. The heavenly stems of Huangdi Neijing are combined with the five elements, that is, A and B belong to wood, C and D belong to fire, Wuji belongs to soil, and not to water. According to the law of five elements producing grams, we can know when the corresponding five zang-organs diseases are good and when they are bad.

Extended data:

Ten dry words: encounter, enlightenment, gentleness, firmness, harmony, Tu Youyou, shangzhang, heavy light, mystery and sunshine. Twelve branches said: sleepy, red heart, taking photos, single-handedly, Xu Bao, Yeluo, Dunyi, Qitan, Dayuanxian.

Simplified heavenly stems and earthly branches: "A, B, C, D, E, Ji, G, Xin, Ren, Gui" is called ten heavenly stems, and "Zi, Ugly, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, Hai" is called twelve earthly branches.

Ten heavenly stems and twelve earthly branches are matched in turn to form sixty basic units, and they cooperate with each other in a fixed order to form the chronology of the stems and branches. Heavenly stems and earthly branches's invention had a far-reaching impact, and heavenly stems and earthly branches still uses it today, which is used in calendar, art, calculation, naming and so on.

Baidu Encyclopedia-heavenly stems and earthly branches