International timekeeping delegates have agreed to replace the leap second with a leap hour from next year, aiming to reduce the risk of technical failures adjusting to global time, The Guardian reports.
Delegates from 69 countries voted on Thursday at a conference of the International Bureau of Weights and Measures in Versailles, France, ending decades of debate over how to keep official time aligned with the Earth’s rotation, cited per the report.
Under the new system, coordinated universal time (UTC) will be allowed to drift by up to an hour from astronomical time before a correction is made.
The first leap hour is unlikely to be needed for thousands of years.
Dr Setnam Shemar, a principal scientist at the UK’s National Physical Laboratory, said the change would reduce risks to computer systems and national infrastructure while maintaining the link between global time and the Earth’s rotation.
According to The Guardian, atomic clocks provide precise timing for communications, satellites, financial trading and electricity grids, while the Earth’s rotation fluctuates due to changes in its core, oceans and atmospheric currents.
Since 1972, 27 leap seconds have been added to keep UTC aligned with astronomical time, but the Earth’s recent acceleration has raised the prospect of a negative leap second, requiring a second to be removed.
The Guardian notes that scientists estimated a 30 percent chance of a negative leap second being needed within the next decade, prompting officials to bring forward the decision.
Previous leap-second adjustments have caused technical problems. Shemar said some systems froze or went offline in 2012, while Reddit and LinkedIn experienced outages and Qantas flights were delayed.
A negative leap second could pose greater risks because some software has never been tested for one, Shemar said, adding that checking systems worldwide would be costly for companies.
The proposal faced opposition from the UK, which has historical ties to Greenwich Mean Time, and Russia, which raised concerns about its Glonass satellite navigation system.
Dr Christian Bizouard, director of the IERS Earth Orientation Centre in Paris, supported the decision. “It is a long way off,” The report quoted him as saying of the first leap hour.