1. Computer-related problems beginning January 1, 2000 caused by programming that coded years with only 2 digits; ambiguity arises in the year 2000, whether 00 represents the year 1900 or 2000, and calculations based on it may fail or produce incorrect results; the bug did not cause as much damage as feared
   "Despite widespread panic, the millennium bug caused relatively few problems when the year 2000 arrived"

Derived forms: millennium bugs

Encyclopedia: Millennium bug