Formula for judging leap year in normal year

The formula of leap year is a leap every four years, not a leap in a hundred years, a leap in 400 years, and a leap in 3200 years. When the year number is divided by four, the rest is leap year, 366 days, February 29th, year number divided by four, surplus 123, normal year 365, February 28th, divisor 400, and the rest is leap year. A leap year is a year in which a leap day (that is, February 29th) is added to the normal year of the Gregorian calendar (that is, 365 days) and the year is adjusted to 366 days. The introduction of leap year aims to make up for the incompleteness of the earth's orbit around the sun. The accurate calculation of leap year is closely related to the accurate correspondence between the solar calendar and the sun. By correctly calculating leap years, the consistency between the solar calendar and the sun can be guaranteed.