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 calendar was used globally for more than 16 centuries but the discrepancy between the calendar dates and the actual time of the spring equinox of the Northern Hemisphere accumulated.

The confusion grew: "February 30, 1712, came into existence in Sweden when the Julian calendar was restored and two leap days were added that year." Sweden’s final conversion to the Gregorian ...

Thursday (Feb. 29) is "leap day," an artifact that dates back to the year 46 B.C. Find out how this calendar oddity came to be.

In honor of Leap Day, this read is for the history nerds. Ever wonder how America caught our calendar up with the rest of the world? In September 1752, we skipped over 11 days.

In the Julian calendar, the new year began on March 25. So March 24, 1701 would be followed directly by March 25, 1702. The Gregorian calendar, as we know today, begins on January 1. ...