24 solar terms handover (accurate to the second)

The handover of the 24 solar terms is divided by the "fixed gas method". It can't be accurate to seconds, only to days.

The method of "fixing qi" divides the sun's annual motion trajectory into 24 equal parts, each of which is a solar term, and each solar term has three cycles. The ancients called solar terms "qi", and 24 solar terms were 24 qi, which were divided into solar terms and middle qi: the first qi at the beginning of each month was called "solar terms"; The second "Qi" in the middle of the month is called "Zhong Qi". In this way, there are 12 solar terms and 12 neutral terms throughout the year, which together are exactly "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 19.

[ 19×0.2422+3.87]-[( 19- 1)/4]=8.9874-4=4

So the beginning of spring date of 20 19 is February 4th.