Abstract: A date reminder calendar includes a plurality of stacked sheets each representing a different date. Each of the sheets is provided with an elongate marking area which is adapted to be marked in a manner readily distinguishable from similar areas which have not been marked. Each sheet is formed with a plurality of elongate parallel openings or slots which are successively smaller in relation to the marking area and each of which is aligned with another marking area on another sheet. By stepping or displacing the marking areas from each other on successive sheets of a group of sheets to avoid overlap, a marked area becomes larger and more prominent with the removal of each successive sheet to thereby increasingly signify the imminency of the date and the reminder associated with the marked area.