The lunations are supposed to consist of twenty-nine and thirty days alternately, or the lunar year of 354 days; and in order to make up nineteen solar years, six embolismic or intercalary months, of thirty days each, are introduced in the course of the cycle, and one of twenty-nine days is added at the end.
The Year Is Luni Solar, And, According As It Is Ordinary Or Embolismic, Consists Of Twelve Or Thirteen Lunar Months, Each Of Which Has 29 Or 30 Days.
Thus The Duration Of The Ordinary Year Is 354 Days, And That Of The Embolismic Is 384 Days.
The Distribution Of The Embolismic Years, In Each Cycle Of 19 Years, Is Determined According To The Following Rule: The Number Of The Hebrew Year (Y) Which Has Its Commencement In A Gregorian Year (X) Is Obtained By The Addition Of 3761 Years; That Is, Y=X } 3761.
If The Remainder Be 3, 6, 8, 14, 17 Or 19 (O), The Year Is Embolismic; If Any Other Number, It Is Ordinary.