Well, each state decides whether or not February 28 or March 1 will be the day you are eligible to get your license. Most states, however, consider March 1st the official day. For instance, the Michigan Vehicle Code states that people born on February 29th "are deemed to have been born on March 1st. There are no rules on when you have a party, however, so really in day in February or March is fair game to celebrate a leap year birthday.
There are about , people in the US and 4 million people in the world who were born on Leap Day. Most years that can be divided evenly by 4 are leap years. The Gregorian calendar is closely based on the Julian calendar, which was introduced by Julius Caesar in 45 BC to fix the Roman calendar including adding a couple extra months. The Julian calendar featured a month, day year, with an intercalary day inserted every fourth year at the end of February to make an average year of But because the length of the solar year is actually This may not seem like a lot, but over the course of centuries it added up.
Until in the 16th century, the vernal equinox was falling around March 11 instead of March In , Pope Gregory XIII adjusted the calendar by moving the date ahead by 11 days and by instituting the exception to the rule for leap years. This new rule, whereby a century year is a leap year only if divisible by , is the sole feature that distinguishes the Gregorian calendar from the Julian calendar.
To make sure we count that extra part of a day, we add one day to the calendar approximately every four years. Leap years are important so that our calendar year matches the solar year — the amount of time it takes for Earth to make a trip around the Sun. But, if you keep subtracting almost 6 hours every year for many years, things can really get messed up.
For example, say that July is a warm, summer month where you live. If we never had leap years, all those missing hours would add up into days, weeks and even months. Eventually, in a few hundred years, July would actually take place in the cold winter months! This is true of almost every other planet in our solar system. Mars, for example, has more leap years than regular years! A year on Mars is sols, or Martian days.
However, it takes After only years, a calendar without leap years would be off by approximately 24 days. Seasonal days such as the vernal equinox or the winter solstice would, therefore, shift in relation to the months in the calendar. For example, in years, the Northern Hemisphere's autumnal equinox , which falls in late September , would fall in late August , and in a few centuries, August would become a spring month. Is There a Perfect Calendar?
A leap day was added every four years. At the time, leap day was February 24, and February was the last month of the year.
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