Origin of epact
Examples from the Web for epact
The Epact is the number of days which must be added to a lunar year to complete a solar year.Time and Time-Tellers|James W. Benson
It is, however, only used in those years in which the epact 19 concurs with the golden number 19.
The epact thus continues to vary until at the end of nineteen years the new moons return as at first.Time Telling through the Ages|Harry Chase Brearley
Having determined the epact of the year, it only remains to find Easter Sunday from the conditions already laid down.
Thus, when the epact is 17, the new and full moons of March fall on the 13th and 28th.A Budget of Paradoxes, Volume I (of II)|Augustus De Morgan
British Dictionary definitions for epact
Word Origin for epact
Word Origin and History for epact
1550s, "number of days by which the solar year exceeds a lunar one of 12 moons;" also "number of days into the moon on which the solar year begins;" from French épacte (12c.), from Late Latin epacta "an intercalary day," from Greek epaktos, literally "brought in, inported," verbal adjective of epagein "to intercalate, add, bring forward," from epi "on" (see epi-) + agein "to bring, to lead" (see act (v.)).