- the period of about eleven days by which the solar year exceeds the lunar year of twelve months
- the age, in days, of the calendar moon on the first of the year
Origin of epactFrench épacte from Late Latin epactae from Classical Greek epaktai (hemerai), intercalary (days) from epagein, to bring in, intercalate from epi-, on, in + agein, to bring, lead: see act
The period of time necessary to bring the solar calendar into harmony with the lunar calendar.
Origin of epactFrench épacte from Late Latin epacta from Greek epaktē (hēmera) intercalary (day) feminine of epaktos brought in, inserted from epagein to bring in, introduce ep-, epi- epi- agein to lead ; see ag- in Indo-European roots.
- 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