You didn't hear it from me, but a certain auto company's Y2K testing of manufacturing software turned up a single defect that would have shut down plants. ''For ''
'''one '''
''day.'' They're glad they found it. Civilization would not have fallen had they not. But they're really glad they have a giant full-time Y2K testing lab.
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It's not fixed until you test it:

I inherited a project that handled 2 digit Y2K issues with logic like this:
   if year2 = 0 then
      ! This is a NULL date, which requires special application processing...
   else if year2 > 50 then
      year4 = 1900 + year2
   else
      year4 = 2000 + year2
   end if
Careless logic:  It fails for all dates in the year 2000 itself (but works for 2001 to 2050).
Fix was to change the first line to "if year2 = 0 and month = 0 and day = 0 then ..."

(The input could not be changed to 4 digit years, because you can't change the ANSI X.12 EDI standards that easily.  ;-)

Also, unaware of implementation techniques such as the above, upper management was claiming that this software would handle all 4 digit dates well into the future -- a highly misleading claim.
(...wait until we hit the "year 2050 crisis!")
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CategoryHistorical