What are the causes of common and leap years?

The most fundamental reason is that the Earth's orbit around the Sun is 365 days, 5 hours, 48 minutes and 46 seconds (conjunction), which is a tropical year. The common year of the Gregorian calendar is only 365 days, which is about one day shorter than the return year, and the remaining time is about one day every four years, so the fourth year adds one day at the end of February, so that the length of the calendar year of that year is 366 days, and this year is a leap year.

There are 97 leap years in the current Gregorian calendar every 400 years. According to a leap year every four years, the average number of days per year is to be counted out, so that after 400 years, about 3 days will be calculated. Thus three leap years are reduced every 400 years.

Therefore, the Gregorian calendar stipulates that when the year is an integer hundred, it must be a multiple of 400 to be a leap year; A year that is not a multiple of 400, and even a multiple of 4 is not a leap year.

Common and leap years arise for the following reasons:

1.The Earth's orbit around the Sun is 365 days, 5 hours, 48 minutes and 46 seconds (conjunction), which is a return year. The common year of the Gregorian calendar is only 365 days, which is about one day shorter than the return year, and the remaining time is about one day accumulated every four years, so one day is added at the end of February of the fourth year to make the length of the year 366 days, and this year is a leap year.

2.A year in which there is no leap day in the solar calendar or no leap month in the lunar calendar is a common year. The common year of the solar calendar is 365 days, the ordinary year of the lunar calendar is generally 354 days or 355 days, and very few lunar years have 366 days, so every two or three years we will encounter a leap year.

A common year is a year in which there are no leap days in the solar calendar or no leap months in the lunar calendar. Leap years are created to compensate for the time difference between the number of days of the year and the actual orbital cycle of the earth caused by the man-made calendar. The number of years in Common Era can be divisible by 4 as leap years, but the number of years in a whole hundred (0 in the single digit and the tenth place) must be divisible by 400 to be a leap year (e.g. 1900 is not a leap year), and the others are ordinary years.

There are 365 days in a normal year and 366 days in a leap year and 29 days in February. The 28th day of February in a normal year in the Gregorian calendar. There are 366 days in a leap year (31, 29, 31, 30, 31, 31, 30, 30, 31, 31, 30, 31, 30, 30, 30 and 31 from January to December).

First, the meaning is different.

1. Leap year: It is established to make up for the time difference between the number of days of the year and the actual orbital cycle of the earth caused by the artificial calendar.

2. Ordinary year: refers to the year when there is no leap day in the solar calendar or no leap month in the lunar calendar; Crops are harvested in an ordinary year.

Second, the development is different.

1. Leap year: every four years; There is no leap in 100 years, and then in 400 years.

2. Ordinary years: those that are divisible by 400 are leap years, and the others are ordinary years.

Third, the characteristics are different.

1. Leap year: Where there is a leap day in the solar calendar (February is the 29th day), the leap year (the year is more than the leap year. The difference in time between the lunar calendar and the return year).

2. Ordinary year: 365 days in a normal year in the solar calendar, 354 days or 355 days in a normal year in the lunar calendar, and 353 days in rare cases.

In general, a year divisible by 4 is a leap year, and a year not divisible by 4 is a common year. For example, 1988 and 2008 are leap years; 2005, 2006 and 2007 were normal years.

But if it is a century year (that is, a whole hundred years), it is a leap year only if it is divisible by 400, otherwise it is a common year. For example, 2000 is a leap year, 1900 is a common year, February has 29 days, and February of a normal year has only 28 days.

The time it takes to revolve around the sun is called a year. Because the time it takes for the Earth to revolve around the Sun is about 365 days, 5 hours, 48 minutes and 46 seconds. Therefore, the Gregorian calendar stipulates that there are common years and leap years.

A year with 365 days as a year is called a common year. A year with 366 days as a year is called a leap year. The calculation method for ordinary years and leap years is "one leap in four years, no leap in one hundred years, and another leap in four hundred years".

According to this calculation, the year of the Common Era that is not divisible by 4 is a common year, the "year of a hundred" that is divisible by 4 is a leap year, the "year of a hundred" that is not divisible by 400 is a mean year, and the year of the Common Era that is divisible by 400 is a leap year, and the number of years of the Common Era that is divisible by 400 is a leap year. For example, 1992 is a leap year, 2000 is a leap year, and 2100 is a common year.

A leap year in the Gregorian calendar is 366 days, a common year is 365 days, and any year that is divisible by 4 is a leap year, such as.

1996, 2012, 2020;

And 2011 and 2020 are not leap years.

But in a year of a hundred thousands, the one that must be divisible by 400 is a leap year, such as 2000, 2400; And 1500 and 2100 are not leap years.

Divide the non-whole 100 by 4, divide the whole 100 by 400, if it is not divisible by the common year, what can be divisible is the leap year. February in a common year has a total of 28 days, while February in a leap year has 29 days. The reason for the emergence of leap years is actually to make up for the fact that there is a certain difference between the number of days in the year and the actual rotation period of the earth due to some artificial legislative provisions in the creation of the annual calendar.

Therefore, the year in which the time difference is made up is called a leap year. But there is no direct relationship between leap years and leap months.

A leap year is a year that is divisible by 4 or a hundred years is divisible by 400, and other years are common years.

The difference between a leap year and a peaceful year is that it is in February, with a leap year having 29 days in February and a normal year having only 28 days in February.

There are 13 months in a leap year and 12 months in a normal year, for example, the leap year is April, which is two lunar April, called leap years, and a common year is a year and a year.

The difference between a leap year and a peaceful year is as follows:1. The meaning is different.

Leap year: a leap year that is not a whole hundred years and is divisible by 4; For a hundred years, it is a leap year that can be divided by 400 divisible gods.

Ordinary years: All years except leap years are common years.

2. The total number of days in a year is different.

Leap year: 366 days in a year, February 29 more than in a normal year.

Peacetime: 365 days a year.

3. The basic explanations are different.

Leap year: Established to compensate for the difference between the number of days of the year and the actual orbital cycle of the earth caused by the requirements of the artificial excavation calendar.

Ordinary year: refers to a year in which there are no leap days in the solar calendar, or there are no leap months in the lunar calendar.

Summary. The reason for the occurrence of leap years, the usual explanation is that there are many days, hours, and minutes in a year, and after rounding up 365 days, there is still a surplus, and after the accumulation reaches one day (24 hours), one more day is added, and the year in which one more day is added is a leap year.

Why do common and leap years occur? What factors are involved?

The reason for the occurrence of leap years, the usual explanation is that there are many days and hours and minutes in a year, and after 365 days, there is still a surplus of brightness, and after the accumulation reaches one day (24 hours), one more day is added, and the year in which the wheel is destroyed and one more day is a leap year.

The most fundamental reason is that the Earth's orbit around the Sun is 365 days, 5 hours, 48 minutes and 46 seconds (conjunction), which is a tropical year. The ordinary year of the Gregorian calendar is only 365 days, which is about one day shorter than the return year of lead in the chain, and the remaining time is about one day accumulated every four years, so at the end of February of the fourth year, Peshiga adds one day, so that the length of the year becomes 366 days, and this year is a leap year.

Kiss You can take a look at the reason for it every four years.

This is what is commonly said: every four years, no leap in a hundred years, and then another leap in four hundred years. For example, 2000 is a leap year and 2100 is a normal year.