The Y2K Problem
The Y2K ProblemThe Y2K Problem!!!
What is Y2k? In one sentence, Y2k is "...the inability of computer programs at the year 2000 to interpret the correct century from a recorded or calculated date having only two digits to indicate the year".[Center for Computer Systems Engineering]
What does that mean? It means that many of our computer systems, although sensitive to date and time, have been programmed with a piece missing -- the century portion of the date. These systems were created by humans, who are used to dealing with dates in context using a shorthand that omits the century. (What car do you drive? A '92 Ford, or a '96 Chevy. When did you graduate? Class of '76.) Unfortunately, when the calendar rolls over from 1999 to 2000, such systems will not have the contextual smarts to process our shorthand dates correctly. Some of these computer systems will produce obviously silly results, good for a laugh at the office. Some will produce subtle errors that may be passed on, undetected at the source, in an ever-expanding circle of bad data. And some systems will stop working altogether.
How might systems fail? Let's look at an example program in which the omitted century is assumed to be '19' and the program's function is to figure out how old you are. If you were born in 1958, then in 1999 this program will calculate your age as 99 minus 58, or 41. That's fine, but what happens when the century rolls over to '20' in the year 2000? In this program, the year will appear as '00' but the century will still be assumed to be '19' -- so the program will calculate your age as 00 minus 58, or -58. Then, depending on the program's error-handling capacity, it might abnormally end or otherwise stop running; or it might send the negative age to another program (which might then fail); or it might omit the sign from the number and pass your age off as 58. The last example is the most insidious, as 58 is not an unreasonable value for an age. It's wrong in this case, but it could easily be propagated throughout other systems without being detected.
Why should I care? The good news is that Y2k is almost completely limited to computer hardware and software....
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