831572-A is referenced by 3 patents.
831,572. Date indicators. SINGLETON, J. S. March 17, 1958 [July 3, 1957], No. 21019/57. Class 106 (4). A date indicator comprises a pair of cubes each face of which bears a zero or a single numeral so distributed between the faces that any number from one to thirty-one can be displayed. The cubes may be made of wood, plastic or metal, they may be solid or hollow and may be formed by folding suitable blanks. One arrangement of numerals is shown in Figs. 2 and 3 wherein one symbol can represent 6 or 9. Another cube can be used to display day names using one symbol to represent M or W. Instead of numerals dots may be arranged on the faces as in dominoes and one zero would have to give place to nine dots as 6 and 9 would need a face each.