I believe that some friends will have some questions about the problem of leap years: How do you feel that you are always in leap years? What exactly is a leap year? Why leap years? How to judge a certain year, whether it is a leap year?
Why do some friends have such a feeling, as if they are always in leap years? It is most likely because the leap month in the lunar calendar is understood together with the leap year in the solar calendar.
In fact, the solar calendar has a leap year, and the lunar calendar only has a leap month.
The leap month of the lunar calendar, that is, in the 12 months of the year, has an additional month and becomes 13 months. This is not the same thing as a leap year in a solar calendar year.
So in the solar calendar, what exactly is a leap year? Why leap years?
We all know that there are 365 days in a year, which is the number of days of the year in the solar calendar. However, in fact, the earth circles the sun, and the real time taken is 365.24219 days.
Obviously, in this way, we will calculate 0.24219 days less per year, and every 4 years, we will calculate almost one day less.
Of course, those who are less calculated must be made up, or they will suffer losses.
So a leap year was set.
So what's the leap? How do you know if a year is a leap year?
In fact, the leap year of the solar calendar is to add 1 day every 4 years to February. That is, February has changed from 28 days to 29 days.
So, if you want to know a certain solar calendar year, is it a leap year? The solution is actually very simple, that is, to divide the number of years to 4, if the result is an integer, then this year is a leap year.
But then there is a problem, that is, if you add 1 day every 4 years, it is actually equivalent to 0.0312 days.
What if you do too much? Subtract, of course.
Thus there is a leap year of the century. The specific method is that the number of the year is an integer multiple of 100, which must be divided by 400, and if the result is an integer, it is a leap year; if it is not an integer, it is not a leap year.
So, how do you tell if a year is a leap year? That is, when the number of years in this year is not an integer multiple of 100, the number of years is divided by 4, and if the result is an integer, this year is a leap year, and vice versa. When the number of years of the year is an integer multiple of 100, the number of years is divided by 400, and if the result is an integer, the year is a leap year, and vice versa.
This is how leap years of the solar calendar are calculated. Is it as long as you understand, it is actually very simple?