GREGORIAN Calendar

, so called from Pope Gregory the 13th, is the new or reformed Calendar, shewing the new and full moons, with the time of Easter, and the other moveable feasts depending upon it, by means of epacts disposed through the several months of the Gregorian year.

Gregorian Epoch, is the epoch or time, from which the Gregorian calendar, or computation, took place. This began in the year 1582; so that the year 1800 is the 218th of this epoch.|

Gregorian Telescope, a particular sort of telescope, invented by Mr. James Gregory. See Telescope.

Gregorian Year, the new account, or new style, introduced upon the reformation of the calendar, by Pope Gregory the 13th, in the year 1582, and from whom it took its name. This was introduced to reform the old, or Julian year, established by Julius Cæsar, which consisted of 365 days 6 hours, or 365 days and a quarter, that is three years of 365 days each, and the fourth year of 366 days. But as the mean tropical year consists only of 365ds 5hrs 48m 57sec. the former lost 11min. 3sec. every year, which in the time of Pope Gregory had amounted to 10 days, and who, by adding these 10 days, brought the account of time to its proper day again, and at the same time appointed that every century after, a day more should be added, thereby making the years of the complete centuries, viz 1600, 1700, 1800, &c, to be common years of 365 days each, instead of leap years of 366 days, which makes the mean Gregorian year equal to 365ds 5hrs 45m. 36sec.

This computation was not introduced into the account of time in England, till the year 1752, when the Julian account had lost 11 days, and therefore the 3d of September was in that year, by act of parliament, accounted the 14th, thereby restoring the 11 days which had thus been omitted. See Year.