Abstract: A perpetual calendar system comprising: a first array of letter positions, each letter position in the first array denoting a position corresponding to a digit in Gregorian numerical system; a second array of numbers corresponding to digits in the Gregorian numerical system; and a third array of symbols comprising a plurality of groups of years, wherein each group corresponds to a related letter position and a related number in the first array and the second array respectively, such that a combination of: the related letter position from the first array, the related number from the second array, and the plurality of groups of years in the third array is used to locate a calendar for a year of interest, and wherein the combination corresponds to a page index in the perpetual calendar system constituted by a plurality of pages, each page having a calendar identified by the corresponding page index.

Abstract: A perpetual calendar system comprising: a first array of letter positions, each letter position in the first array denoting a position corresponding to a digit in Gregorian numerical system; a second array of numbers corresponding to digits in the Gregorian numerical system; and a third array of symbols comprising a plurality of groups of years, wherein each group corresponds to a related letter position and a related number in the first array and the second array respectively, such that a combination of: the related letter position from the first array, the related number from the second array, and the plurality of groups of years in the third array is used to locate a calendar for a year of interest, and wherein the combination corresponds to a page index in the perpetual calendar system constituted by a plurality of pages, each page having a calendar identified by the corresponding page index.