The expression Y2K, shorthand for the year 2000 (Y=year; 2=two; K=the symbol for 1,000), helped define the closing days of the twentieth century by spotlighting some pitfalls of the computer age. Y2K represented a major problem—some called it a crisis of global proportions—caused mainly by older computers whose programmers and software designers failed to foresee what could happen in the year 2000. Often called "the Y2K bug," this problem came about because early computer designers used only a two-digit year—uniformly dropping the "19" that stands at the beginning of every year from 1900 to 1999. What the designers failed to take into consideration was the problem posed by the year 2000. Computer logic meant the machines would translate the numbers 00 not as the year 2000 but as 1900. In the closing days of the century, the world was put on notice that computers using the two-digit formulation...