Today was a touch longer - for an instant - after a leap second was added to Australian time
The atomic clock at the National Measurement Institute in Sydney had an extra second added to it at 9.59.59am AEST on Wednesday - in line with atomic reference clocks around the world.
Physical Metrology general manager Bruce Warrington says without leap seconds our clocks wouldn't be accurate.
Things can get out of whack due changes caused by a slowing rotation of the Earth, leading to official "time" adjustments.
"At the end of the century it might be about a minute, maybe a little more," he said of the difference.
"We can't speed up the Earth so we slow down the clocks.
"You may not notice it... but there's lots of technical infrastructure underneath it, that to work properly has to account for that second - computer networks, financial markets and telecommunications systems."
The last time a leap second was added on June 30, 2012, it caused issues for some websites including reddit and LinkedIn, while 50 Qantas flights were reportedly delayed when the check-in system was temporarily affected.
But Mr Warrington says they are optimistic everyone has prepared appropriately this time around.
"I certainly hope so. I expect so. One of the key things is for people to be aware that this is coming so they have a chance to prepare their systems."
