Every year, media outlets around the world see how much they can do outdo each other for the most preposterous April Fool’s Day gag.

It was 40 years ago that ABC‘s This Day Tonight program unveiled a corker which attracted national attention at the time and more recently has gone global!

Nigel Starck, in 1975 a reporter for TDT in Adelaide, had come up with the idea to run an April Fool’s Day story on metric time. His inspiration came from reading a newsletter regarding converting cars to metric measurements — kilometres instead of miles — which was happening in the early 1970s.

What will they convert next? Clocks to metric time? Oh, yes! — said the intrepid reporter.

Under the “metric time” scheme, seconds would become millidays, minutes become centidays, and hours become decidays.

He managed to find a willing accomplice in South Australian deputy premier Des Corcoran, assisted by some metric clocks whipped up by the ABC props department.

In the days before Photoshop, they also managed to place a crudely-mocked metric clock face on a picture of the Adelaide town hall. It probably looked convincing on 1970s TV sets!

The story gained widespread reaction — including confused viewers turning up at department stores seeking to buy a metric time clock… or asking how to convert their clocks to metric. It also gained national exposure, including an article in TV Times magazine a few weeks later.

Back in 2008, this website retrieved the original article and blogged it for April Fool’s Day. As a result the prank got picked up by the American Museum Of Hoaxes website which ranked it at the time at #15 in their Top 100 April Fool’s Day hoaxes of all time.

On the 40th anniversary of the original TDT story, Dr Starck, as he is now as an adjunct senior lecturer at the University of South Australia, said it was remarkable the impact that story had over his long and varied career: “In 40 years of journalism, travelling the world, interviewing prime ministers, reporting on war and famine and flood, covering international sporting events, and announcing President Nixon’s resignation, it remains the only story that has brought me any sort of lasting recognition. And it was a hoax.”

“I do think listing as No. 15 is a bit mean of them. It’s surely ‘Top 10’ standard!”

But the internet is a harsh place, and as time has moved on and heaps more hoaxes have gained attention, the Top 100 list has been reviewed and sadly the metric time story has been bumped down… to 65th place!

Rest assured, it’s still our favourite here!