All these examples and many more depend on the correct number of days, months, and years between two dates. Many inventive people are attempting to devise a way around this deficiency. Ordering of data is the second most troublesome problem with six-digit dates. Dates are used very frequently to sort computer records into ascending, descending or identical-date order. And this ordering is important.
Computer programs expect to find the records containing the dates in the correct place.
Computer records are created, for example, for a students expected tenure in a university program. In 1996 we created date-based records for each of four years for a student entering the undergraduate program. These were the years associated with each of the years in our four-year programs beginning with the current year, current semester. Since some students begin in the Spring semester, we did the same thing in January of this year. But the computer doesn't see it that way.