Some of the reasons they went with the two digit for the date code were to save disk space-- as well as reduce the number of keystrokes needed to enter a date-- software engineers came up with a standard MM/DD/YY date field. I would not not doubt billions of lines of code not have to altered to fix this problem.

The year 1998, for example, is stored as "98" in most files. Unless those files are changed, the year 2000 will be stored as "00." Which in Microsoft the largest supplier of operating systems is not recognized and will go to their "base date" 1980. (They have fixed some of this see Y2K .) The Y2K fix is mind boggling -- it requires companies to examine all their applications and correct every line of code that includes a two-digit date field. Technically, it's grunt work. Managerially, it's a nightmare. This most daunting part is that large companies can not afford to miss deadline. When the year 2000 arrives, most of the programs they use will be useless. Unless the applications are fixed and available on January first, all businesses will lose the ability to do business.