Dominical Letter - Dominical Letter of A Year

Dominical Letter of A Year

The dominical letter of a year is defined as the letter of the cycle corresponding to the day upon which the first Sunday (and thus every subsequent Sunday) falls. Leap years have two Dominical Letters, the second of which is the letter of the cycle preceding the first; the second letter describes the portion of the year after the leap day.

The Gregorian calendar repeats every four hundred years. Of the four hundred years in a Gregorian cycle, there are 43 common years with Dominical letter A, 43 common years with B, 43 with C, 43 with E, and 43 with G. Of common years with Dominical letter D and F, there are 44 for each. Of the leap years, there are 13 each with BA, DC, and GF; 14 each with ED and FE, and 15 each with AG and CB.

In the Julian calendar, the cycle is 28 years, 7 of which are leap years, and the remaining 21 are common years. Each of the seven Dominical letters is split evenly among the 21 common years, and each of the seven double letters for leap years, BA, CB, DC, ED, FE, GF, and AG, occur once in every 28-year cycle.