Why do we need a leap year?
Leap Year Explained
- The Gregorian calendar, which now serves as the standard calendar for civilian use worldwide, has two common years and leap years. A common year has 365 days and a leap year of 366 days, with the extra, or interplanetary day designated as the February 29 leap year occurs every four years to help synchronize the calendar year with the solar year, or the length of time it takes the earth to complete its orbit around the sun, which is about 365¼ days.
- The length of the solar year, however, is a little less than 365¼ days for about 11 minutes. To compensate for this discrepancy, it omits the leap year every four years three times.
- In other words, a century year cannot be a leap year if it is divisible by 400. So no 1700, 1800 and 1900 were not leap years, but 1600, 2000 and 2400 are leap years.
What are your chances of being born on leap day?
- About 1 in 1,500.
When is the birthday party?
- If you are born in a leap year, you can get your driver’s license on February 28 or March 1? It is an ambiguous question to be decided by each state. Most states, however, consider March 1, the official day. For example, the Michigan Vehicle Code says that people born on February 29 “will be deemed to have been born on March 1st.”
How many people were born on leap day?
- There are about 187,000 people in the US and 4 million people in the world who was born on leap day.
The rules for determining a leap year.
- Most years that can be divided evenly by 4 are leap years.
Exception: Century years are not leap years unless they can be evenly divided by 400.
When it originated the leap year?
- The Gregorian calendar is based closely on the Julian calendar, which was introduced by Julius Caesar in 45 BC. The Julian calendar had 12 months a year of 365 days, with an interplanetary day inserted every four years in late February for an average of 365.25 days’ year. But as the length of the solar year is actually 365.242216 days, the Julian year was too long for 0078 days (11 minutes and 14 seconds).
- This may not seem like much, but over the centuries are added, until the 16th century, the vernal equinox was falling around March 11 instead of March 21 In 1582, Pope Gregory XIII set the calendar moving date ahead by 11 days and by setting the exception to the rule for leap years. This new rule, whereby a century year divisible by only if it is a leap year 400, is the only feature that distinguishes the Gregorian calendar in the Julian calendar.
- After the Gregorian reform, the average length of the year was 365.2425 days, an even closer approximation to the solar year. At this rate, it will take more than 3,000 years for the Gregorian calendar to gain one extra day in error.