20 1 1 light snow solar terms

The 22nd is quite certain.

Calculation formula of light snow date: [Y*D+C]-L

Interpretation of the formula: Y= two digits after the number of years, D=0.2422, L= leap year, 2 1 century C=22.36, and 20th century =23.08.

For example, the date of light snow in 2088 = [88× 0.2422+22.36]-[88/4] = 43-22 = 2 1.165438+1October 21light snow. Exception: 1978 plus 1 day.