epact

American  

[ee-pakt] / ˈi pækt /

noun

1. the difference in days between a solar year and a lunar year.

2. the number of days since the new moon at the beginning of the calendar year, January 1.

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epact British  

/ ˈiːpækt /

noun

1. the difference in time, about 11 days, between the solar year and the lunar year

2. the number of days between the beginning of the calendar year and the new moon immediately preceding this

3. the difference in time between the calendar month and the synodic month

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Etymology

Origin of epact

1545–55; < Late Latin epacta < Greek epaktḗ, noun use of feminine of epaktós added, equivalent to ep- ep- + ag ( ein ) to lead + -tos verbid suffix

Example Sentences

In the calendar, Table IV., look for April, and the epact 28 is found opposite the second day.

From Encyclopaedia Britannica, 11th Edition, Volume 4, Part 4 "Bulgaria" to "Calgary" by Various

It should be borne in mind that the epacts are obtained by successively adding eleven to the epact of the former year, and rejecting thirty as often as the sum exceeds or equals that number.

From Our Calendar by Packer, George Nichols

Subtract the epact from 57, divide by 7, and keep the remainder, or 7, if there be no remainder.

From A Budget of Paradoxes, Volume I by Smith, David Eugene

The value of L is always given by the formula for the dominical letter, and P and l are easily deduced from the epact, as will appear from the following considerations.

From Encyclopaedia Britannica, 11th Edition, Volume 4, Part 4 "Bulgaria" to "Calgary" by Various

There were thirty-six or 4×9 of these in the Egyptian year, at the end of which an epact of five days was added, each day being consecrated to one of the five chief gods.

From The Fundamental Principles of Old and New World Civilizations by Nuttall, Zelia