| |
Julian
calendar
The calendar introduced by Julius
Caesar in 46 B.C. to replace the lunar calendar. The Julian
calendar provided for a year of 365 days with a leap year
every four years, or an average year length of 365.25 days.
Because the solar year is slightly shorter, the Julian
calendar gradually moved out of phase with the seasons and was
superseded by the Gregorian calendar, introduced by Pope
Gregory XIII.
Julian
date
A Julian date is expressed as the number
of days elapsed since January 1, 4713 B.C. For example, the
date October 9, 1995 (Gregorian calendar) would be expressed
as 2,450,000 on the Julian calendar. Julian dates are useful
for finding elapsed times between events that may be many
years apart, as in astronomy. |
