How is the specific time of the 24 solar terms calculated?

The current 24 solar terms are divided by the method of "fixing qi". Depending on the sun starting from the vernal equinox (longitude zero, at this moment the sun shines vertically on the equator), every advance of 15 degrees is a solar term; After a week's operation, I returned to the vernal equinox, which is a tropical year with 360 degrees, so it is divided into 24 solar terms.

Date calculation

General formula of longevity -[y× d+c]-l

Y= the last two digits of the year, D=0.2422, L= the number of leap years, and C depends on the solar terms and year.

265438+20th century beginning of spring c value =3.87.

For example: beginning of spring date 20 17.

[ 17×0.2422+3.87]-[( 17- 1)/4]=7.9874-4=3

So the beginning of spring date of 20 17 is February 3rd.

Extended information 24 solar terms songs

The plum blossoms in the early spring are particularly bright, and the apricot blossoms after the rain are particularly fresh;

Lulin thunder, butterfly dance between flowers at the vernal equinox.

Qingming kite broken, Grain Rain tender tea jade companion,

Mulberry fruits are like cherries in the long summer, and silkworms are cultivated in the small man.

Before mango seedlings enter the palace, the summer solstice rice and flowers are like white practice;

Summer breeze urges early-maturing beans, and Chi Pan enjoys red lotus in hot summer.

Beginning of autumn knows how to make people fall asleep, and sunflowers smile in summer.

The white dew returns to the geese, and the autumn equinox smells like osmanthus.

Cold dew vegetable seedlings are green, and the first frost reed flowers are floating all over the sky;

Beginning of winter reported good news, reported three rewards, and light snow and goose feathers flew in pieces.

The snow is very cold, the plum blossoms are crazy in the wind, and the winter solstice is full of snow.

Little cold wanderers are homesick, and they celebrate reunion at the end of the cold year.

Baidu encyclopedia-24 solar terms

Baidu Encyclopedia-24 solar term song