What's the difference between year, month, day and time of year?

The main branch timing method is based on the ground branch. It starts at 23 o'clock every day, and then ugly, cloudy, hairy, Chen, Si, noon, Wei, Shen, You, Xu, Hai and so on. The name of each time unit is "hour", which is equivalent to two hours now, and a cycle is exactly twenty-four hours. The function of heavenly stems is to expand the counting scale and unify the stem-branch system.

Branches and branches can be used not only for timing, but also for calculating years, months and days. Among them, the legend of the year and day has been handed down from the starting point of Xuanyuan Huangdi era. And month and time can be calculated from year and day by formula.

The formula is: "A has given birth to A, B Geng C is the beginning, C Xin starts from E, Ding Ren Geng Zi lives, E Gui starts from where, and Ren Zi is the true way." It means that every year, every year, next month must be Jiazi month, Jiazi day and Jiazi day must also be Jiazi, and so on.

The second month is 1 1 month of the summer lunar calendar, also known as the winter month (but it is the first month of the lunar week). The winter solstice is usually in this month of each year. According to the legend mentioned above, the origin of the trunk and branch timing system is defined as a winter solstice time, that is, the time of Jiazi Year, Jiazi Month and Jiazi Day.

It should be noted that the annual winter month mentioned here does not refer to the winter month of a certain year, but refers to the last year. This is due to the change of dynasties in the past, which led to the change of the first month of the calendar, but it was no longer changed, but the first month has become the first month, and the main and branch timing systems could not be disconnected to adapt to the changed first month, so it became like this.

Besides, there are other names for "stem" and "branch", that is, Yang and Yin, but they are not ugly or anything.