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.

It wasn't a bad model for measuring the years. The only trouble was that he was 11 minutes and 14 seconds out.

Such a small amount of time may seem a trifling matter. Even when it added nearly three-quarters of an hour every four years, few would have noticed the difference.

However, as time marched on it became a bit more of an issue. And by the late 16th Century, with 10 extra days unaccounted for, Pope Gregory XIII decided to take drastic action.

The challenge to find a system to rectify this ever-increasing problem was huge. As the on-line Catholic Encyclopedia recalls, throughout the Middle Ages many had tried and failed to devise a solution.

'For this purpose, it was necessary . . . not only to determine with accuracy the exact amount of the Julian error, but also to discover a practical means of correcting it,' the encyclopedia said.

In the end it was done with breathtaking efficiency: In his papal bull of 1582, Gregory simply ordered that October be shortened by 10 days, with the 15th following the fourth.

While speedy, it must have made keeping appointments that month rather difficult and would have played havoc with Filofaxes.

Still, having long been accused of being vague, Lai See would have appreciated having a legitimate excuse for not knowing what day it was.

But even that wasn't the end of it. For a start, initially only Catholic countries observed the new calendar.

Protestant countries, never jumping out of their skins to acknowledge papal decrees, were reluctant to change, while the Greek Orthodox Church didn't adopt the new calendar until the start of this century.

Sweden's solution was particularly bizarre. Waiting till the start of the 1700s, they phased in the Gregorian calendar over 40 years by dropping every leap year, leaving them out of step with everyone.

Before they got into step with everyone else, the Swedes first returned temporarily to the Julian calendar and then had a double leap year in 1712.

To prevent a recurrence of the previous mistake, Gregory decided to omit three leap years in every four centuries in his calendar, thus eliminating three superfluous days that would have occurred under the Julian system.

This brought us back to normal - well almost. In fact, the length of the Gregorian calendar still exceeds the true astronomical measurement of a year by 26 seconds.

So Pope Gregory can continue to rest in peace knowing that his small miscalculation won't cause carnage for quite some time.

It will be another 35 centuries before this will translate into an error of a whole day.

Meanwhile, back in the late 20th Century, the rest of the world continues to wait with bated breath to see what calamitous events will unfold as we party the millennium away.

But it appears the potential impact of computer error remains a mystery on the mainland, where debate among some of the population centres on whether it is a millennium bug, worm or otherwise.

A survey released earlier this week found that with less than four months before the end of the year, more than one in four mainlanders have no idea what the millennium bug is.

Agence France-Presse reported that a poll conducted in 11 major mainland cities revealed that only 63 per cent of respondents could provide a clear definition of the bug, while only 8.4 per cent had a rough idea of the cause and potentially harmful effects of the Y2K problem.

Which leaves a disturbing 28.6 per cent who are ignorant about it, giving definitions of the problem ranging from worms, viruses and fossils to corrupt officials.

Awareness or otherwise, what is most alarming is the mainland's dependence on outdated equipment and pirated software, and time is running out to overcome this.

Or is it? Lai See has an idea. To give Y2K technicians some breathing space, maybe we can go back to the Julian calendar for a while.

Those 10 days we lost in 1582 may suddenly come in handy.