Abstract: An automatic calendar is provided which permits a regular change in the display from the end of the month to the first day of the next month to be achieved without requiring adjustment over a prolonged period of time, by employing a unique arrangement of numerals providing a display of date. The calendar comprises a unit's day display member having an indication of numerals in the sequence of 0, 1, 1, 2, 3, 4, 5, 6, 7, 8 and 9 at an equal interval, and a tens' day display member having an indication of numerals in the sequence of 0, 1, 1, 2, 2 and 3 or a repeated sequence thereof.