Golden Number

Golden Number for any year is the number of that year in the Metonic Cycle (q.v.); and, as this cycle embraces nineteen years, the golden numbers range from one to nineteen. The cycle of the Greek astronomer Meton (432 B.C.) came into general use soon after its discovery, and the number of each year in the Metonic cycle was marked in golden colours in the Roman and Alexandrian calendars. Hence the origin of the name. Since the introduction of the Gregorian calendar the point from which the golden numbers are reckoned is 1 B.C., as in that year the new moon fell on the 1st of January; and, as by Meton's law the new moon falls on the same day (1st of January) every nineteenth year from that time, we obtain the following rule for finding the golden number for any particular year. 'Add one to the number of years, and divide by nineteen; the quotient gives the number of cycles and the remainder gives the golden number for that year; and if there be no remainder, then nineteen is the golden number, and that year is the last of the cycle.' The golden number is used for determining the Epact (q.v.) and the time for holding Easter (q.v.).