This year is a leap year, meaning Feb. 29 was added as the 366th day on the calendar. Here's what to know about its meaning, ...

Every four years, an extra day is added to the calendar, But even with leap day, the math doesn't exactly, well, math.

11 In Sweden in the leap year 1712, the country marked February 29 and 30! Two extra days were added to the calendar to move from the Swedish calendar to the Julian one. 12 Someone born on ...