Chapter 32 Arrangements for the third section of the year, month and day

An important content in the calendar is how to arrange the leap month.Before the intercalation cycle was abolished, the lunar year was alternately arranged with 30 days in the big month and 29 days in the small month.An ordinary lunar year consists of 12 months, with a total of 354 days, and there is a difference of more than 11 days from the return year. For two or three years, one month must be added to make the average age basically equal to the return year.Before the middle of the Western Han Dynasty, the leap month was arranged at the end of the year.After the early days of the Western Han Dynasty (104 BC-101 BC), the month without middle energy was changed to the leap month.

The intercalation at the end of the year is often corrected when the dislocation between phenology and month is obvious, which is very unreasonable.In the Tang Dynasty, Li Chunfeng abolished the intercalation cycle in the Linde calendar, and stipulated that the month without middle energy should be the intercalary month.The modern theoretical value of the synodic month is 29.53059 days, which is about one day shorter than the interval between two meridians.If the Wangri of the first month coincides with Zhongqi, then after 32 months, the cumulative difference between the two exceeds one month, and there will be a month without Zhongqi during this period, which will cause the Zhongqi that should belong to this month to shift. to the next month.If no measures are taken, subsequent Zhongqi will be postponed one by one.This month without middle-qi generally appears around the 16th month. It is stipulated that this month is a leap month, which means that the intercalation at the end of three years is advanced to one and a half years, so that the deviation between the phenology and the monthly sequence does not exceed half a month. It is indeed relatively Reasonable.The month order of the leap month still uses the month order of the previous month, which is called "a leap month".

Today, the lunar calendar used in China is more reasonable. The year that contains 13 months between two winter solstice is a leap year, and the first month without a middle energy in a leap year is a leap month.All in all, intercalation solves the corresponding problem of lunar year and phenology. Using Dingshuo to arrange big and small moons was also adopted by Li Chunfeng first, although he was not the first to advocate it.Before that, the big and small moons were arranged alternately, and it was only after about 16 months that the big moons appeared once.The movement of the moon varies from fast to slow, and when it moves fast, the interval between new moons will be smaller than the average.When walking slowly, it will be greater than the average.The Chinese lunar calendar starts with the moon as the beginning of a month.If you want to make the first month of each month coincide with the new moon, you need to correct the average value according to the actual speed. The corrected new moon is the real new moon, which is called fixed moon.It is not surprising that sometimes there will be three consecutive small months or four consecutive large months after using Dingshuo to arrange the calendar.

What time of the day is used as the starting point?Why midnight and not some other time?Originally, in human history, sunrise, sunset, midday (that is, noon), and midnight have all been used as the beginning of a day.The daytime is the first to be denied. It is obviously extremely inconvenient for people to span two days in the continuous activities of the day.The timing of sunrise and sunset changes with the seasons, with early sunrise and late sunset in summer, late sunrise and early sunset in winter, so it was abolished more than 2,000 years ago.Only midnight is the most suitable date cut-off point.When Zishi is subdivided into Zichu and Zizheng, Zizheng becomes the beginning of a day, which coincides with the current Gregorian calendar system.

The beginning of the year refers to the season in which a year begins.After the Qin and Han Dynasties, the first year of the year was unified on the day when the beginning of spring meets the new moon.Since the lunar year is shorter than the return year, the first day of some years may be earlier than the beginning of spring, but it will be adjusted as before after the leap month is installed, basically ensuring that each year starts with spring. Summarizing the content written above, compare the various elements of the Chinese lunar calendar with the current Gregorian calendar, and list them in the following table: