The millennium bug refers to the existence in many computer software packages of a six-digit date rather than an eight-digit date. Computers speak the language of mathematics. Every question posed to a computer program is answered either "yes" or "no" and represented in binary code as either a one or a zero. Since computers recognize math symbols, a computer can add 97 + 1 and get 98. When the computer is presented the problem 99 + 1 and the answer does not fit in the required two-digit field, the computer's response is an error, or worse, a shut-down.

What caused this error in planning to occur? In the 1960s and 1970s, when computers were coming into widespread use, one of the largest concerns to programmers was the amount of memory available to the user. With this concern in mind, programmers searched for ways to cut memory requirements. Reducing dates to six digits (01/31/99, for...