Why Do We Need Leap Years?

     

Leap Years are needed to keep our calendar in alignment with the Earth's revolutions around the sun.
It takes the Earth approximately 365.242199 days – or 365 days, 5 hours, 48 minutes, and 46 seconds (a tropical year)– to circle once around the Sun.
However, the Gregorian calendar has only 365 days in a year, so if we didn't add a day on February 29 nearly every 4 years, we would lose almost six hours off our calendar every year. After only 100 years, our calendar would be off by approximately 24 days!

http://www.timeanddate.com/date/leapyear.html

Fun Facts about the Leap Year

• The Egyptians are responsible for our knowledge that the solar and human calendars are not in sync.
• Instead of 365 days, the Earth takes an extra 5 hours, 48 minutes and 46 second to go around the Sun.
• The Romans (Julius Caesar) added February 29th as a leap day in the Julian calendar, with the once every 4 years rule. It took another 1500 years (till 1582) for the Gregorian calendar to apply the system we use now.
• Only years divisible by 4 have leap days.
• No year that can be divided by 100 has a leap day unless it is also divisible by 400. That’s why 1900 was not a leap year but 2000 was.
• Leap day is the day when women are allowed to propose to men (though these days most women don’t wait if that’s what they want to do.) According to tradition, this practice started in the fifth century.
• Since those born on February 29th only have a birthday every 4 years (most celebrate the day before or day after), they can claim to be much younger than their calendar years. Here’s a handy chart to work out your age in leap years if this applies to you.
• Even decades usually have three leap years (e.g. 2000, 2004, 2008); even ones have two (e.g 1992, 1996)
• Want to know what day of the week Leap Day will be? It occurs on the same day every 28 years.  That means it will be 2040 before Leap Day is on a Wednesday again.
• According to the Guinness Book of Records, one family in the UK has three generations born on February 29th. They are Peter Anthony Keogh (194), Peter Eric Keogh (1964) and Bethany Wealth (1996).
• Not everyone follows the Gregorian calendar. For example, the lunisolar Chinese calendar adds a leap month approximately every 3 years. This month takes place at different times in the calendar.
• Sweden once had an extra leap day, February 30th, in 1712.

http://www.parkrideflyusa.com/blog/2012/02/01/fun-facts-leap-year-2012/