Gregorian \Gre*go"ri*an\, a. [NL. Gregorianus, fr. Gregorius
Gregory, Gr. ?: cf. F. gr['e]gorien.]
Pertaining to, or originated by, some person named Gregory,
especially one of the popes of that name.
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
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.
Calendar \Cal"en*dar\, n. [OE. kalender, calender, fr. L.
kalendarium an interest or account book (cf. F. calendrier,
OF. calendier) fr. L. calendue, kalendae, calends. See
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
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
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.
Note: Shepherds of people had need know the calendars of
tempests of state. --Bacon.
Calendar clock, one that shows the days of the week and
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.
n 1: 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 [syn: Gregorian
calendar, New Style calendar]