Usually, February 28 is followed by March 1, but every few years, exceptions occur. In 2020, we have February 29th, and 2024 will be like this as well. Why?
On Earth, a solar year is usually 365 days, which is the amount of time it takes for the Earth to orbit the Sun. Since the gregorian calendar was introduced in 1582, it has stipulated 365 days per year, ensuring that the calendar year coincides with the solar year.
But long ago, clever astronomers discovered that the Earth's orbit around the sun actually took a little longer than 365 days. To be precise, they accurately calculated that it would take 365.242 days for the Earth to orbit the Sun (in other words, 365 days, 5 hours, 48 minutes and 46 seconds).
This means that in reality, there are almost 365 and a quarter of a day a year. Because it was so difficult to put the extra quarter of a day of the year directly on the calendar, the clever Egyptians came up with a good idea. They combined the four extra quarters of the four days of the four years into one day, and added the extra day to the calendar every four years to ensure that the calendar was consistent with the solar year.
The ancient Romans, under Julius Caesar, did the same thing the Egyptians when they invented the modern calendar we use. In fact, they were the first to set the extra day as February 29.
The extra day is called leap day, and the year in which leap days appear is called leap year. Leap characters have several meanings, one of which is to represent the remainder. Because we have merged the remaining time of the next four years into one day ahead of schedule to ensure that our calendar and the Earth orbit the sun equally, we call it leap days.
Is it necessary for us to do this? While adding a day every four years doesn't seem like much now, it accumulates over time. For example, if we ignore the extra time, in a century we will be 25 days apart from the solar year. This means that each season on the calendar will be delayed by almost a month than it actually is. Leap years can solve this problem by synchronizing our calendar with the solar year.
Unfortunately, the calculation of leap days is not as simple as adding one day every four years. Astronomers found that the solar year was actually 11 minutes and 14 seconds less than 365 and a quarter of a day. This means that people will add 3 more days every 400 years, calculated by adding one day every four years.
To solve this problem, the ancient Romans decided to calibrate by reducing leap years every 400 years. They devised the rule that only one of the three "full hundred" years could be rated as leap years. For example, 1700, 1800 and 1900 are not leap years, but 2000 is a leap year.
An easy way to tell if a full hundred years is a leap year is to see if the number of years can be divisible by 400. So, 2100, 2200 and 2300 are not leap years, but 2400 are leap years.
People born on February 29 are often referred to as "leaplings, or leapers." In non-leap years, common years, they usually celebrate birthdays on February 28 or March 1. Some of them will, when they are old, use the fact that they were born in a leap year as the secret of their "opportunism". For example, an 84-year-old man born in a leap year might say he is only 21 because he has only had 21 birthdays (once every 4 years).
Leap year (also known as intercalary year or bissextile year) is a year that has one day more than a normal year. If the lunisolar calendar is used, then a leap year is a year that is one month more than the normal year. Leap years ensure that the year on the calendar is synchronized with the year in the astronomical sense and at the seasonal level in this way. Because seasons and astronomical events do not repeat according to a fixed number of days, but the number of days of the month on the calendar is relatively fixed, the corresponding dates of the corresponding seasons and astronomical events will also deviate from the previous dates. This shift can be corrected by adding a year or a month. Non-leap years are called flat years.
For example, in the Gregorian calendar, each leap year has 366 days instead of 365 days, changing from a normal 28 days to 29 days by adding an angel to 2 months. These extra days are distributed in years that can be divisible by 4 (the entire hundred years that cannot be divisible by 400 are not included). Similarly, in the Hebrew calendar, which uses the luni-solar calendar, the month of Adar Aleph, the thirteenth synodic month, is increased to 7 times every 19 years of the twelve plastic moons of the common year to ensure that the seasons marked by the calendar do not deviate from natural changes. In the Bahá'í Calendar, leap days are added to the calendar when needed to ensure that the coming year begins with the vernal equinox.
BY: wonderopolis
FY: Memories
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