How to calculate the "October solar calendar" of the Yi people?

The basic content of the Yi people's "October Gregorian Calendar" is to mark the days with 12 animals as cycles, including tigers, rabbits, dragons, snakes, horses, sheep, monkeys, chickens, dogs, pigs, rats and cows, without ordinal numbers and branches.

As the date is marked by the zodiac, one zodiac week is 12 days, and each cycle of the three zodiac weeks is one month, with 36 days per month. The week of 30 Zodiac is 1 year, that is, 360 days.

One year 10 months, so you don't have to worry about the zodiac. Calculate the age, every 10 months is one year old. After the end of one year, five more days will be put at the end of the year, which is not included in the last month of last year or the first month of next year. As New Year's Day, also known as "October Year", there are 365 days in the whole year. Every four years, an extra "New Year's Day" is 366 days, with an average of 365.25 days per year. This is similar to the time for the earth to go around the sun for 365.422 days, science.

Yi calendar records the days according to the zodiac, which has its regularity. If last year's 1 month was the year of the tiger, because every month is 3 animal weeks, which is 36 days; If New Year's Day is 5 days, then the next month 1 is the Year of the Sheep; If New Year's Day is 6 days, then the next 1 month is the Year of the Monkey. If the next year's 1 month is a sheep day or a monkey day, the first day of each month will always be a sheep day or a monkey day.

In this way, the first day of the same year 10 and all the corresponding days are the same. Next year's 1 month date only needs to be pushed back by 5 or 6 zodiac signs on the basis of the previous year's date.

The end of May in the October calendar is the Torch Festival, and the first day of the Lunar New Year is the Spring Festival, which is equivalent to the two "Tanabata" in which the Big Dipper is divided into the north and the south. It is two traditional major festivals of the Yi people.

Torch Festival is held around June 24th of the lunar calendar, and Spring Festival is held around New Year's Eve of the lunar calendar. One is hot, the other is cold, and the season is quite accurate. The October Gregorian calendar also divides a year into 10 "periods", using five elements of earth, copper, water, wood and fire.

They are represented by men and women respectively: January native male, February native female, March bronze male, April bronze female, May water male, June jellyfish, July wooden male, August wooden female, September fire male and October fire female. The order of these five elements is: summer soil, autumn copper, winter water, spring wood and fire at the turn of spring and summer, which is equivalent to spring wood, summer fire, autumn gold and winter water of Han nationality.

The Yi calendar distinguishes men and women according to the five elements, so a year is divided into five seasons, and each season includes two months of men and women in the same element, totaling 72 days. These five seasons actually represent the five directions that the sun passes through on the celestial sphere: east, west, south, north and middle.

There are 10 months in a year here, two months are female, one month is male, male and female are yin and yang; A year is divided into five seasons, and each season is represented by five elements: earth, copper, water, wood and fire. These five elements are the five elements. Therefore, the October solar calendar of the Yi people already contains the ideas of Yin-Yang and Five Elements.

The astronomical knowledge of the Yi people is recorded in the Yi classic "Southwest Branch One", "Cosmic Man Literary Theory" and many Bimo classics.