1984 Comparison between Calendar and Lunar Calendar
In the Gregorian calendar (Gregorian calendar), a year with leap days is called leap year, which is generally 365 days and 366 days. Because the earth's cycle around the sun is 365 days, 5 hours, 48 minutes and 46 seconds (365,438+09 days), which is the tropic year, the Gregorian calendar sets a year as 365 days. The remaining time is about one day in four years, plus February, so the normal year is 365 days, February is 28 days, leap year is 366 days, and February is 29 days. Therefore, there are 97 leap years every 400 years, with an additional day at the end of February, and leap years have 366 days. Calculation method of leap year: the number of years in the calendar year can be divisible by four, which is a leap year; Divided by 100 but not divided by 400 is a normal year; Leap years can be divisible by 100 or 400. For example, 2000 is a leap year, but 1900 is not.