I remember one program. What they used to call dusty deck, after the deck of punched cards they were on. Dusty from years sitting on a shelf. It had one constant for two very different purposes. The equivalent of using foo for both the range of values for the month and for the hour in a date-time because they both happen to be 12. Lots of luck in Israel, where the Hebrew calendar (1..13) and military time (0..23) are often used.