Gregorian calendar, introduced in 1582, replaced Julian calendar to correct its inaccuracies, particularly the overly ...

Next year will be a ‘leap year’, meaning there will be 366 days in the calendar year. Here’s how many of those days will be ...

Every fourth year, those extra quarter-days get added to the calendar to make one full day – February 29. 2 This means every leap year has 366 days! 3 A leap year happens when the year can be ...

We've used leap years for over 2,000 years so our calendars are more in sync with the Earth’s rotation around the Sun. What is a leap year? Generally we define a year as 365 days, but a full ...