But every leap year one day must be added to the lunar month in which the 29th of February is included.
It Will Be Remembered That In A Leap Year There Are Always Two Dominical Letters, One Of Which Is Employed Till The 29Th Of February, And The Other Till The End Of The Year.
It was thus an effective compromise between the solar year and the lunar month, and contrasts very favorably with the intricate and clumsy years of other ancient systems. The leap-year of the Julian and Gregorian calendars confers the immense benefit of a fixed correspondence to the seasons which the Egyptian year did not possess, but the uniform length of the Egyptian months is enviable even now.
Then, Since Every Year Which Is Not A Leap Year Ends With The Same Day As That With Which It Began, The Dominical Letter Of The Following Year Must Be L 1, Retrograding One Letter Every Common Year.
As The Number Of Days In The Week And The Number In The Year Are Prime To One Another, Two Successive Years Cannot Begin With The Same Day; For If A Common Year Begins, For Example, With Sunday, The Following Year Will Begin With Monday, And If A Leap Year Begins With Sunday, The Year Following Will Begin With Tuesday.