updated 9/21/2005 2:57:29 PM ET 2005-09-21T18:57:29

Hold on a second! Britain's Royal Astronomical Society on Wednesday called for a public debate on the proposed abolition of leap seconds, a tiny end-of-year adjustment to keep clocks in synch with the earth's rotation.

The International Telecommunication Union (ITU) will meet in Geneva in November to debate a proposal to abolish leap seconds after 2007. The next leap second comes at the end of this year.

Mike Hapgood, secretary of the Royal Astronomical Society, said the debate has practical implications for computers, global positioning systems and for those who study phenomena — such as tides — which are related to the earth's rotation.

"The debate has been rather closed, mainly among timing experts," Hapgood said in a telephone interview.

There are two systems for time-keeping:

  • International Atomic Time, or absolute time-keeping, based on atomic clocks.
  • Universal Time, the classic system based on the rotation of the earth.

Since International Atomic Time was introduced in 1958, it is now 32 seconds ahead of ordinary time because of fluctuations in the rate of the earth's rotation.

To manage the discrepancies, the International Telecommunication Union in 1971 developed a system called Coordinated Universal Times. This system uses the leap to keep everyday time accurate within 0.9 seconds.

Leap seconds normally are declared every year or two. But because of a recent stabilization in the earth's rotation, there have been no leap seconds since 1998.

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