تعريف gregorian calendar في الإنجليزية الإنجليزية القاموس.
The calendar currently used in the western world. It replaced the Julian calendar and was devised to halt the slow drift of the vernal equinox towards earlier in the year
the system of arranging the 365 days of the year in months and giving numbers to the years from the birth of Christ, used in the West since 1582 (Because it was introduced by Pope Gregory XIII). Solar dating system now in general use. It was proclaimed in 1582 by Pope Gregory XIII as a reform of the Julian calendar. By the Julian reckoning, the solar year comprised 365 1 4 days. The addition of a "leap day" every four years was intended to maintain correspondence between the calendar and the seasons; however, a slight inaccuracy in the measurement of the solar year caused the calendar dates of the seasons to regress almost one day per century. By Pope Gregory's time, the Julian calendar was 10 days out of sync with the seasons; in 1582, to bring the vernal equinox (and thus Easter) back to its proper date, 10 days were dropped (October 5 became October 15). Most of Catholic Europe soon adopted the new calendar; Great Britain and its colonies (1752) and Russia (1918) followed much later. The Gregorian calendar differs from the Julian only in that no century year is a leap year unless it is exactly divisible by 400 (e.g., 1600, 2000). A further refinement, the designation of years evenly divisible by 4,000 as common (not leap) years, will keep the calendar accurate to within one day in 20,000 years
the solar calendar now in general use, introduced by Gregory XIII in 1582 to correct an error in the Julian calendar by suppressing 10 days, making Oct 5 be called Oct 15, and providing that only centenary years divisible by 400 should be leap years; it was adopted by Great Britain and the American colonies in 1752