Beginning of spring is on February 4th, 2020 17: 03 and 12 seconds, corresponding to the lunar calendar on Tuesday, the 11th day of the first month. Beginning of spring is divided from astronomy. According to the position of the sun on the ecliptic, the year is divided into 24 equal parts, that is, the ecliptic is divided into 24 equal parts, and each equal part accounts for 15 degrees of the ecliptic.

The formula for calculating beginning of spring is [y * d+c]-L. ..

Interpretation of the formula: Y= year (take the last two digits), D=0.2422, L= leap year, c depends on solar terms and year, 2 1 century c value = 3.87, and in the 22nd century c value = 4. 15. So the complete algorithm is: multiply the last two digits of the year by 0.2422 and add 3.87 to get an integer result, and then subtract the leap year to get beginning of spring Day.

For example, if the calculation steps of beginning of spring date in 2020 are [20× 0.2422+3.87]-[(20-1)/4] = 9-5 = 4, then February 4, 2020 is beginning of spring date.

When the sun runs along the longitude of the Yellow River from zero 15 degrees, it is called "a solar term", which runs 360 degrees every year and * * * experiences 24 solar terms. When the sun reaches 3 15 degrees along the longitude of the Yellow River, it is called "beginning of spring".