Why is leap year

Too bad if your birthday fell on one of the days in between! To do this, leap years began more than two millennia ago, when the scientific advisers to Roman emperor Julius Caesar spotted that the years were not properly aligning with the seasons. So in 45 BC, Caesar decreed there would be an extra day every four years to compensate.

From that point onwards, the Gregorian calendar — as it became known — has been working well. Other cultures have different calendars based on the cycles of the moon rather than the sun and Earth. The Islamic Al-Hijra calendar has days and adds an extra day every four years as does the traditional Chinese lunar calendar.

Please explain: Why do we have leap years? Faculty of Science and Engineering. Our Stories. Science and Technology. 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 So, you would sometimes have to add a sol to help the calendar catch up.

In a 10 year period, four of the years would have sols and six of the years would be leap years with sols. For more information on leap years, visit this NASA page. What Is a Leap Year? The Short Answer:. It takes approximately If you are born on a Leap Year, can you get your driver's license as early as February 28th? 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.