Once every four years, an extra day is added to the month of February. That year is considered a leap year, and February 29 is known as a leap day. Leap years exist because it takes the Earth 365 days ...

It's not every year that you see February 29 on the calendar -- and it's not technically every four years either. Thursday is officially leap day. For some, its birthdate, or a day for special deals ...

Saturday is Feb. 29, a.k.a. leap day, a date that appears on our calendars only once every four years. Leap day is added because it takes the Earth 365 days, five hours, 48 minutes and 45 seconds to ...