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Working Group 7A of the International Telecommunication Union's Study Group 7 may sound like an anonymous international committee like any other. But this is no quango of grey bureaucrats in greyer suits arguing over the desired colour of toilet paper. At the heart of this group's discussions is something of fundamental importance to anyone who has ever taken a second to fall in love or to score a goal: time itself, and how to define it.
Unbeknown to most people there is not a single accepted way of telling the time, but several different scales running concurrently. The differences are usually small, but the scales can be as much as 30 seconds apart and the gap between them is growing steadily.
Aircraft navigation systems tell a different time from the watches of passengers, pilots and air traffic controllers. Experts are warning that this could spell disaster.
"We should only have one type of timescale throughout the world," says Bill Klepczynski, a time expert who advises the federal aviation administration. "There's a possibility for danger."
The International Telecommunication Union - the global body that agrees time standards - is taking the issue seriously, and has set up the working group to advise it what to do. "We're trying to gather data on how people are using time, what sort of problems they have and whether or not a contiguous timescale would be beneficial," says Ron Beard, who heads the group.
But the plans have not pleased everyone, and arguments about the best way forward are rattling the usually steady world of timekeeping.
The problem arises because the Earth cannot keep time as accurately as modern atomic clocks, which count the steady shaking of atoms. These atomic clocks replaced the motion of the Earth as the world's official timekeeper in 1967. The pull of the moon is gradually slowing our planet down, so every now and then our clocks are halted for a second to let it catch up.
The first of these "leap seconds" was introduced in 1972, mainly as a favour to astronomers and others who still relied on the old- style celestial time. A further 31 leap seconds have been added since, most recently on December 31 1998.
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