There was a millennium bug joke - an airline captain told his passengers that one of the aircraft's engines had cut out because of the millennium bug but it was OK because the other one was still working. Then his co-pilot told him that the clock on that one was a minute slow.
Of course, no airlines fell from the sky at midnight on 31 December 1999 and even the dozens of chips in some of the USA's nuclear missiles that were causing concern turned out to be just fine.
So, that's that then, you might think. But no.