Leap Year
It's all because of the Earth's rotation and the fact that a day isn't actually an exact 24 hours. Slooh astronomer Bob Berman explained to AccuWeather, that each rotation of Earth takes 23 hours, 56 minutes and 4.1 seconds, to be precise. The orbit around the sun is also imprecise: Earth takes 365 days, five hours, 48 minutes and 45 seconds to complete a full trip. The Gregorian calendar, created by Pope Gregory in 1583, factors in the uneven timing by including an extra day in February every four years as a leap year. However, an extra day every four years is an overcorrection to the calendar, and Pope Gregory accounted for this, too. For every century year, the calendar resets by skipping leap year. Every 400 years, it does not reset and maintains the leap year. The year 2000 was a year that did not reset; therefore, it had an extra day. For instance, someone born on a Leap Day is known as a leapling, though the odds of being a leapling are exceedingly slim....