Unlike the Julian Calendar, that proceeded it by more than 1,600 years, the Gregorian Calendar established a leap rule that was more specific and detailed in order to prevent dates drifting.

A calendar notation in which the date is represented by one number. For example, the Julian date for December 11, 1942 is 2430705; while December 12, 1942 is 2430706. The Julian date is widely ...

In a leap year, we add this extra day to the month of February, making it 29 days long instead of the usual 28. The idea of an annual catch-up dates back ... known as the Julian calendar.