Accurate calculation method of leap year in Gregorian calendar (according to a tropical year of 365 days, 5 hours, 48 minutes and 45.5 seconds)

① A leap year is a year in which ordinary years are divisible by 4 and cannot be divisible by 100. (For example, 2004 is a leap year, and 190 1 is not. ) 221century is a leap year. (For example, 2000 is a leap year, 1900 is not. )

(3) For a year with large values, if the year can be divisible by 3200 and 172800, it is a leap year. For example, 172800 is a leap year, but 86400 is not (because 3200 is divisible, but 172800 is not) (this is calculated according to 365 days in a tropical year, 5h48'45.5').