What is the 72-hour formula?

The formula of seventy-two seasons is five days, three seasons are qi, six seasons are hours, four seasons are years old, and seventy-two seasons are twenty-four solar terms a year. Each climate corresponds to a phenological phenomenon, which is called climate response. Among them, the plant climate should be germination, flowering and fruiting.

Animals should start vibrating, singing, mating, migrating, etc. Abiotic climate should include initial freezing, thawing and thunder. The time series changes of 72 climate events reflect the overall situation of climate change in a year.

Seventy-two explanations

Seventy-two periods are compiled according to the signs of natural phenomena such as animals and plants in the Yellow River basin, which are used to explain the changes of solar terms and serve as the basis for agricultural activities in the Yellow River basin.

5 days is a cycle, and 365 days a year (normal year) is 72 cycles. In order to correspond to the twenty-four solar terms, it is stipulated that three periods are one period (qi), and there are 72 periods in a year.

Weather "weather" should include abiotic and biological categories. The former includes "water begins to dry up", "easterly winds thaw", "rainbows begin to appear" and "the ground begins to freeze". The latter includes animals and plants, such as "the swan goose comes", "the tiger begins to make love", "Ping begins to live", "Bitter vegetable show" and "the peach blossom begins to bloom".

Someone made a convenient memory formula for the seventy-second period: "The fifth day is waiting, the third period is waiting for the weather, the sixth period is waiting for the weather, and the fourth period is years old. There are twenty-four solar terms in a year. Each climate corresponds to a phenological phenomenon, which is called climate response.