Most people are familiar with the two-digit shortcut that programmers took in keeping data compact.
And most programmers will readily admit that they did not expect their code to run for more than a couple of years or so. And worst of all, some exist only as binary executables, their source code long lost in a programmer's desk or a mislabeled tape. So programmers around the world are working at warp speed first to find all the programs, then to locate the source code and start the tedious search for date dependencies. Data within a single program can be fixed with some effort, but when these pieces of information are shared among multiple programs, they often are in a database. Now changes in one program may mean mandatory changes in dozens of other programs.