Most of us will have better things to do than debate when the new millennium really starts.
Come January 1, 2000, we will be too preoccupied with drink or relief that our plane to Bali didn't crash or that our life savings didn't disappear because of computer failure to bother about academic arguments over the next thousand years.
But as our hangovers linger and our party hats droop, we might spare a thought for our European forebears, whose transition from the Julian calendar to a Gregorian one makes the Y2K problem seem like a minor technical hiccup.
While they didn't have the headache of computer glitches threatening to pull large aircraft out of the sky and involuntarily close the global financial system, renaissance ecclesiastical authorities did have to unravel more than 1,600 years of inaccuracy.
The man to blame for this was Julius Caesar, whose calendar the Western world relied upon for more than 1,600 years.
In 46 BC, Caesar calculated that the true length of a year was 365 days and six hours - or a quarter of a day, hence a leap year.