Jiujiu, also called Jiujiu in winter, is a folk method to calculate the date of warm flowers in spring and cold days in China. Generally, March and April are the coldest time, which is the coldest time of the year. When you count to nine "nine days" (998 1 day), spring will be deep and warm, and everything will be full of vitality. It's time for spring ploughing.
Law No.9 is passed down from mouth to mouth among the people in our country, which has a history but lacks records. As for when it originated, there is no exact information.
Calculation method
From the solstice of winter to the unhealed day of winter (after the winter, the first unhealed day is called "Jiaojiu", which means the beginning of cold), every nine days is a "nine", the first nine days are called "Yijiu", the last nine days are called "Erjiu", and so on, until "Jiujiu" and "Jin Jiu Peach Blossom", the weather will be warm. As the saying goes, "Summer solstice is three years old, and winter solstice is nine years old." .
It is generally the coldest in April and September, which is the coldest period of the year; By the ninth five-year plan, the cold had disappeared and spring was blooming. ?
The correct algorithm of "counting nine" begins from winter to the first nonunion day in the future. Therefore, the specific date of "September" every year is not fixed, depending on the first nonyl day after the winter solstice.
Another view is that the number nine is counted from the date of winter solstice, so the specific time of "nine" is counted from the date of winter solstice every year, and each "nine" is fixed on the ninth day, 18 and the 27th day after winter solstice. The algorithm of "counting nine" from winter to the sun is not very accurate.