Crossword clues for epact
epact
- Moon's age on Jan. 1
- Solar-lunar year gap
- Calendar moon's age at New Year's Day
- Time excess of a sort
- Differential in solar and lunar time
- Lunar-solar year gap
- Lunar-solar differential
- Solar year excess
- Solar-lunar equalizer
- Solar year/lunar year differential
- Number of days that a solar year differs from a lunar year
- Lunisolar difference
- Lunar-year word
- Astronomer's word
- Difference in days between the lunar and solar year
- Astronomical difference
- Solar-year excess
- Calendar period
- Solar-vs.-lunar year period
- Solar year's excess over lunar year
- Solar-lunar year difference
- Astronomy discrepancy
- Excess of solar over lunar year
- Moon's age on January 1
- Solar-lunar time differential
- Period that unifies calendars
- Period of time, in astronomy
The Collaborative International Dictionary
Epact \E"pact\ ([=e]"p[a^]kt), n. [F. ['e]pacte, fr. Gr. 'epakto`s brought on or in, added, fr. 'epa`gein to bring on or in; 'epi` on, in + 'a`gein to bring or lead. See Epi-, and Act.] (Chron.) The moon's age at the beginning of the calendar year, or the number of days by which the last new moon has preceded the beginning of the year.
Annual epact, the excess of the solar year over the lunar year, -- being eleven days.
Menstrual epact, or Monthly epact, the excess of a calendar month over a lunar.
Douglas Harper's Etymology Dictionary
1550s, "a number attached to a year to show the number of days into the calendar moon on which the solar year begins;" 1580s, "number of days by which the solar year exceeds a lunar one of 12 moons;" from French épacte (12c.), from Late Latin epacta "an intercalary day," from Greek epakte (plural epaktai, in epaktai hemerai "intercalary days"), from fem. of epaktos "brought in, imported, alien," verbal adjective of epagein "to add, bring forward," also "intercalate," from epi "on" (see epi-) + agein "to bring, to lead" (see act (v.)). Related: Epactal.
Wiktionary
n. the time (number of days) by which a solar year exceeds twelve lunar months; it is used in the calculation of the date of Easter
Wikipedia
The epact (Latin epactae, from Greek: epaktai hèmerai = added days) has been described as the age of the moon in days on January 1, and occurs primarily in connection with tabular methods for determining the date of Easter. It varies (usually by 11 days) from year to year, because of the difference between the solar year of 365–366 days and the lunar year of 354–355 days.
Usage examples of "epact".
S, the epact J must be diminished by unity every centesimal year, excepting always the fourth.
M, we have already stated that in the Gregorian calendar the epacts are increased by unity at the end of every period of 300 years seven times successively, and then the increase takes place once at the end of 400 years.
In those years in which the line of epacts is changed in the Gregorian calendar, the golden numbers are removed to different days, and of course a new table is required whenever the solar or lunar equation occurs.
Instead, however, of employing the golden numbers and epacts for the determination of Easter and the movable feasts, it was resolved that the equinox and the paschal moon should be found by astronomical computation from the Rudolphine tables.
It is fortunate that the difference is one of eleven days, for as that is the number which is added every year to the epact our epacts are almost the same.
In the first side of the Cube (id est the Chronoscopium Universalis) you can see eight wheels arranged in perennial cycles represent the Calendars of Julius and of Gregory, and when recur the Sundays and the Epacts, and the Solar Circle, and the Moveable and Paschal Feasts, and novilunes and plenilunes, quadratures of the sun and moon.