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.

A bag clip comprises a pair of opposing jaws configured for resilient movement between an open position in which the jaws are apart from one another and a closed position in which the jaws are adjacent one another. An indicator wheel attached to the clip includes indicators that may correspond to dates on which the bag was opened and the clip was attached. A second indicator wheel may be included, in which the first wheel may correspond to months of the year and the second wheel may correspond to days of the month.

A bag clip comprises a pair of opposing jaws configured for resilient movement between an open position in which the jaws are apart from one another and a closed position in which the jaws are adjacent one another. An indicator wheel attached to the clip includes indicators that may correspond to dates on which the bag was opened and the clip was attached. A second indicator wheel may be included, in which the first wheel may correspond to months of the year and the second wheel may correspond to days of the month.