Leap Year Facts
In case you were unaware, or could care less about such things, 2008 is a leap year, which means that it has 366 days instead of the usual 365 days in an ordinary year. The extra day added in a leap year is February 29, which is called an intercalary day or a leap day.
Leap years are necessary because the exact length of a year is 365.242 days, not 365 days, as commonly known. Basically, leap years occur every four years, and years that are evenly divisible by 4 (2004, for example) have 366 days.
However, there is one exception to the leap year rule involving century years, like the year 1900. Since the year is slightly less than 365.25 days long, add-ing an extra day every four years results in about 3 extra days being added over a period of 400 years. For this reason, only one out of every four century years is considered a leap year. Century years are only considered as leap years if they are evenly di-visible by 400. Therefore, 1700, 1800, 1900 were not leap years, and 2100 will not be a leap year.
The Egyptians were the first to come up with the idea of adding a leap day once every four years to keep the calendar in sync with the solar year. Later, the Romans adopted this solution for their calendar, and Julius Caesar became the first to designate February 29 as the leap day in 45 BC. The early Romans had a 355-day calendar and to keep festivals occurring around the same season each year a 22- or 23-day month was created every second year. Caesar decided to simplify things and added days to different months of the year to create the 365-day calendar, the actual calculations were made by Caesar's astronomer, Sosigenes. Every fourth year following the 28th day of Februarius (February 29th) one day was to be added, making every fourth year a leap year.
In 1582, 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 400, is the sole feature that distinguishes the Gregorian calendar from the Julian calendar.
Following 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.
LEAP DAY TRIVIA
• What are your chances of being born on leap day? About 1 in 1500.
• How many people were born on leap day? There are about 187,000 people in the U.S. and 4 million people around the world who were born on Leap Day. Some like to refer to themselves as Leapers or Leap Children.