Countries agree to end leap seconds to protect computer networks

Representatives of 69 countries have agreed to stop adding leap seconds regularly, a measure intended to protect computer networks from outages, ERR reported. Countries will let atomic time and astronomical time drift apart and intervene only when the difference reaches a full hour.

The decision was made at a meeting in Versailles, France. Since 1972, 27 leap seconds have been added to official time to keep atomic clocks aligned with the Earth’s rotation.

Atomic clocks measure time using the vibrations of caesium atoms, while the Earth’s rotation varies as natural forces slow or speed up the planet. The two systems therefore do not keep exactly the same pace.

Software developers say leap seconds can disrupt computer systems because companies handle the adjustments in different ways. In 2012, a leap second caused the Reddit social network to crash. Qantas’s ticketing system also failed that day, leaving passengers stranded at airports.

In the past decade, the Earth’s rotation has accelerated, leading scientists to warn that a second might need to be removed from official time. Computer programs are not designed to handle a 59-second minute, creating another risk for global networks.

Setnam Shemar, a scientist at the United Kingdom’s National Physical Laboratory, said reliable synchronisation was essential for telecommunications and electricity networks. An extra second inserted at the wrong moment could disrupt an entire network if software were not updated correctly.

Noël Dimarcq, a metrologist at the Côte d’Azur Observatory in France, called the vote a historic step that would provide an uninterrupted timeline for thousands of years. Georgette Macdonald, head of Canada’s metrology centre, said the new rule would keep atomic time stable for hundreds of years.

Under the new approach, the two time systems will run at their own pace until the difference reaches one hour. Shemar compared the change to daylight saving time, when clocks are shifted by an hour twice a year.

The proposal did not receive unanimous support in Paris. Russian delegates voted against it because the code used by the GLONASS satellite navigation system requires individual leap seconds.