I'm not sure if the millennium bug was a huge scam by the IT industry to get companies spend wads of money on making sure their computers never blew up or was a massive miscalculation because despite warnings that aeroplanes would fall from the sky and everyone's laptop would drop dead at the stroke of midnight on December 31 1999, nothing happened.
With this in mind the same people are now warning of computer Armageddon on June 30th when the Worlds atomic clocks gain a leap second to stay in sync with Earth's rotational time which is slowing down by about two thousandths of a second every day.
The problem is that during the leap second, the computer clock shows 60 seconds instead of simply rolling over to the next minute, or shows the 59th second twice. The computer sees a leap second as time going backward and the machine registers this as a system error, throws a wobbly and the CPU overloads and general carnage all around and we wake up in a post apocalyptic Mad Max World.
Still, i'm sure some IT consultants will do very nicely out of it by charging for a fee to 'fix' the problem and save us all when really, all we need to do it turn the computers off before midnight and back on again just after and the computer will fetch the correct time and nothing blows up because the clock is wrong.