Experts undecided on leap seconds


Timekeeping experts failed Friday to reach a decision on scrapping the practice of adding extra seconds to clocks, a system opponents say causes headaches in a high-tech, interconnected world.

After deferring a decision almost two years ago, members of the 193-nation International Telecommunication Union aim to settle the issue by 2015, but divisions persisted as a week of talks among technical experts wrapped up in Geneva.

Leap seconds are used to keep atomic clocks in sync with Earth’s rotation, which is slowed by the gravitational pull of the sun and the moon. Every time a second is added, computers need to be manually adjusted, a costly practice that boosts the risk of error.

But without leap seconds, ultra-accurate clocks would race ahead of solar time by about 15 seconds every 100 years.

Leap seconds were created in 1971 in an effort to simplify adjustments to Coordinated Universal Time, which had been defined by ITU members in 1963 as a successor to Greenwich Mean Time. They have been added on 24 occasions since then.

Breakneck technological change has increased calls for a move to a continuous, global time scale, given that global navigation or satellite systems require a continuous, uninterrupted time reference and Internet communication straddles borders.