The origin and order of the twelve solar terms

According to the position change of the sun in a year and the evolution order of the ground climate caused by it, the ancients divided the 365th day and the quarter day of a year into 24 segments, and then divided them into 12 months to reflect the four seasons, temperature, phenology and so on. This is the twenty-four solar terms. Every month is divided into two sections, the first section is called "solar terms" and the middle section is called "qi". The twenty-four solar terms are divided into twelve solar terms and twelve qi, and each month has a "festival" and a "qi". "Festival" is the beginning of the month, and the last day of "Qi" is the end of the month. In a month's solar terms, the qi is in the first month (cloudy), the rain in beginning of spring is in February (gross), the vernal equinox is in March (Chen), the Qingming Grain Rain is in April (April), the long summer crops are abundant in May (noon), the midsummer is in June (late), the hot summer is in July (Shen), and beginning of autumn is in summer, August (with) and Baibai.