Feeling that Y2k was little more than a mass marketing heist, many people chose to take no precautionary action to prepare for the millennium. This was, indeed, a great oversight. Although theories on Y2k being highly over-hyped (and overmarketed) were true, Y2k was not without circumstance. It has been discovered that certain computer systems were not Y2k compliant.
As the clock "rolled" from 1999 to 2000, these computers experienced an irreparable glitch. The systems rolled over to April 1 [of an unknown year]. They become trapped in an infinite loop of a perpetual April Fool's Day. As an April Fool's Day prank [by them, on us], the computers opted to lead their operaters to believe that everything was operating optimally.
In brief; certain computers are perpetually set to April 1 [of an unknown year] but as an April Fool's Day joke appear to be functioning normally.