epact
the difference in days between a solar year and a lunar year.
the number of days since the new moon at the beginning of the calendar year, January 1.
Origin of epact
1Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024
How to use epact in a sentence
The epacts were once of some importance in ecclesiastical chronology, being used for finding when Easter would fall.
The New Gresham Encyclopedia | VariousNow, these solar epacts have several practical advantages over the Dominical letters.
Hence, for the construction of a perpetual calendar, there must be thirty different sets or lines of epacts.
Each of the thirty lines of epacts is designated by a letter of the alphabet, which serves as its index or argument.
In that year the omission of the intercalary day rendered it necessary to diminish the epacts by unity, or to pass to the line C.
British Dictionary definitions for epact
/ (ˈiːpækt) /
the difference in time, about 11 days, between the solar year and the lunar year
the number of days between the beginning of the calendar year and the new moon immediately preceding this
the difference in time between the calendar month and the synodic month
Origin of epact
1Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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