gregorian calendar

Webster's Dictionary (GCIDE)

Gregorian calendar, the calendar as reformed by Pope Gregory XIII. in 1582, including the method of adjusting the leap years so as to harmonize the civil year with the solar, and also the regulation of the time of Easter and the movable feasts by means of epochs. See Gregorian year (below).

Gregorian chant (Mus.), plain song, or canto fermo, a kind of unisonous music, according to the eight celebrated church modes, as arranged and prescribed by Pope Gregory I. (called "the Great") in the 6th century.

Gregorian modes, the musical scales ordained by Pope Gregory the Great, and named after the ancient Greek scales, as Dorian, Lydian, etc.

Gregorian telescope (Opt.), a form of reflecting telescope, named from Prof. James Gregory, of Edinburgh, who perfected it in 1663. A small concave mirror in the axis of this telescope, having its focus coincident with that of the large reflector, transmits the light received from the latter back through a hole in its center to the eyepiece placed behind it.

Gregorian year, the year as now reckoned according to the Gregorian calendar. Thus, every year, of the current reckoning, which is divisible by 4, except those divisible by 100 and not by 400, has 366 days; all other years have 365 days. See Bissextile, and Note under Style, n., 7. [1913 Webster]

1.An orderly arrangement of the division of time, adapted to the purposes of civil life, as years, months, weeks, and days; also, a register of the year with its divisions; an almanac. [1913 Webster]

2.(Eccl.) A tabular statement of the dates of feasts, offices, saints' days, etc., esp. of those which are liable to change yearly according to the varying date of Easter. [1913 Webster]

3.An orderly list or enumeration of persons, things, or events; a schedule; as, a calendar of state papers; a calendar of bills presented in a legislative assembly; a calendar of causes arranged for trial in court; a calendar of a college or an academy. [1913 Webster]

Note: Shepherds of people had need know the calendars of tempests of state. --Bacon. [1913 Webster]

Calendar clock, one that shows the days of the week and month.

Calendar month. See under Month.

French Republican calendar. See under Vend['e]miaire.

Gregorian calendar, Julian calendar, Perpetual calendar. See under Gregorian, Julian, and Perpetual. [1913 Webster]

Free On-line Dictionary of Computing

<time> The system of dates used by most of the world. The Gregorian calendar was proposed by the Calabrian doctor Aloysius Lilius and was decreed by, and named after, Pope Gregory XIII on 1582-02-24. It corrected the Julian calendar whose years were slightly longer than the solar year. It also replaced the lunar calendar which was also out of time with the seasons. The correction was achieved by skipping several days as a one-off resynchronisation and then dropping three leap days every 400 hundred years. In the revised system, leap years are all years divisible by 4 but excluding those divisible by 100 but including those divisible by 400. This gives a mean calendar year of 365.2425 days = 52.1775 weeks = 8,765.82 hours = 525,949.2 minutes = 31,556,952 seconds. leap seconds are occasionally added to this to correct for irregularities in the Earth's rotation.

(2007-01-10)