How to calculate leap year-leap year calculation method

How to calculate leap year-leap year calculation method

How to calculate leap year? Do you know the calculation method of leap year? Let me introduce the calculation method of leap year to you!

Calculation method of leap year

Leap year in the western calendar

A year with leap days in the solar calendar is called a leap year, and vice versa, it is 365 days in a normal year and 366 days in a leap year. In the Gregorian calendar year, February in a normal year is 28 days, and February in a leap year is 29 days. February 29th of a flat month in a leap year is a leap day.

Reasons for increasing leap days

At present, the Gregorian calendar takes the tropical year as the benchmark, and a tropical year is about 365.4220 days. Because the average calendar year is only 365 days, it will accumulate 0.24220*4=0.9688 days after four years, which is about equal to one day, so a leap day is added every four years to offset this 0.9688 days.

Calculation method of leap year:

In the Gregorian calendar, most years divisible by 4 are leap years; A year divisible by 100 but not by 400 is not a leap year; Not a leap year divisible by 3200; For example, 1900 is a normal year, 2000 is a leap year and 3200 is not a leap year.

Leap year in China lunar calendar

In the China lunar calendar, a year with a leap month is called a leap year. The general year is 12 months, 354 or 355 days, and the leap year is 13 months, 383 or 384 days.

The law that leap years follow: leap every four years, not leap in a hundred years, and leap again in four hundred years.

Leap year is a year with leap day in Gregorian calendar or summer calendar, and also a year with leap month in China lunar calendar.

Are there 29 days in February of leap year?

There are 29 days in February in the solar calendar this year, which is a leap year. February 29th is a leap day. According to the astronomical society, it is found that the Year of the Monkey is a leap year in 2 1 century (from 2000 to 2099). The similarity between the year of the monkey in the lunar calendar and the leap year in the solar calendar is that both can be divisible by 4. But what can be divisible by 4 is not necessarily the Year of the Monkey, but also the Year of the Rat and the Year of the Dragon. There are 12 times in the Year of the Monkey in the lunar calendar and 1 times in leap years in the solar calendar. So, why should the solar calendar set a leap year?

Now all countries in the world use the solar calendar, also called the solar calendar. The length of solar calendar 1 year is based on the tropic year, which is a cycle of cold and summer. The tropic year is the time interval when the sun travels along the ecliptic and passes through vernal equinox twice in a row. Its length is 365.38+09 days, not an integer.

But the dates of calendars need to be integers, so astronomers divide calendars into flat years and leap years, with 365 days in a flat year and 366 days in a leap year. Set 1 leap day in 4 years, and the leap day in leap year will be added to the last 1 day in February.

Therefore, February in every leap year has 29 days. Astronomers also stipulate that every century year (1600, 1700, 1800, 1900, 2000, 2 100) is a leap year, not only by 4, but also by 400. So 1600 and 2000 are leap years; 1700, 1800, 1900 and 2 100 are not leap years. In this way, in the 400 years, * * * has set 97 leap years, so that the solar term of "vernal equinox" can be kept around March 2 1 for a long time.

According to the budget, the solar calendar we are using now is 1 day older than the return, which takes about 3222 years.

;