Is the time interval between every two solar terms in the twenty-four solar terms the same every year?

The current "twenty-four solar terms" are divided by "constant gas method", that is, each solar term corresponds to a certain position that the earth reaches every time it runs 15 on the ecliptic; The "constant gas method" divides the sun's annual trajectory into 24 equal parts, each 15 is an equal part, and each equal part is a solar term. That is to say, each solar term refers to the sun's revolution relative to the earth 15 (with reference to the earth), and the sun's moving speed is almost the same every year, so the time interval between each solar term is almost the same.

Extended data

Partition calculation

Fixed gas method

The current "twenty-four solar terms" come from the "fixed qi law" formulated by western priests more than 300 years ago, and the "lunar calendar" from the time when western priests formulated the "constitutional calendar" to the present is determined according to the sun's position on the ecliptic, that is, it is divided into 24 equal parts on a "ecliptic" with a circumference of 360 degrees (the apparent path of the sun on the celestial sphere for one year). Therefore, the 24 solar terms are 24 time points, and the specific date of the "point" is the natural result of celestial movement. [ 13]

The method of "solid gas" takes the summer solstice when the sun runs to 90 degrees of the yellow meridian, which is also the tropic of cancer when the sun points directly at the intersection. The current 24 solar terms take the earth's revolution around the sun as a cycle, which basically summarizes the laws of natural phenomena such as the different positions of the sun on the ecliptic at different times of the year, the accurate time of cold coming and summer going, rainfall and snowfall. It began in the beginning of spring and ended in the great cold.

The Gregorian calendar dates in 24 solar terms are roughly the same every year: the first half of the year is around 6th and 2 1, and the second half is around 8th and 23rd. [26]

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.

(Note: Only integers are reserved in the calculation result) [27]?

Reference: 24 solar terms