Year 2000 Problem

the problem caused by software that represents the year date as two digits (such as 99 for 1999) and thus does not recognize that 2000 comes after 1999. Instead, the software interprets 00 as 1900. This causes mistakes in calculations that involve the date.

Dates were originally represented as two digits for two reasons. First, in the 1960s, computer memories were very expensive, and even the largest computers' total memory was far smaller than that of a modern PC. Second, data was stored on punched cards, each of which could hold only 80 characters; the two characters saved by omitting "19" could be used for something else.

Some banks dealt with the Year 2000 Problem as early as 1970 when issuing 30-year loans. In 1998 and 1999, computer users were urged to update all software, and there was widespread panic as news media reported that all types of machinery, even microprocessor-controlled car engines and coffee makers, would fail on January 1, 2000. These predictions proved false; problems occurred in only out-of-date accounting software and the like. Nonetheless, much of the updating was necessary or beneficial for other reasons.