Overview
- Representatives of the International Bureau of Weights and Measures are meeting in Versailles to vote on proposals that could end leap seconds and bring changes into effect as soon as May 20, 2027.
- One proposal would keep atomic UTC steady while redefining the second using newer optical clocks, another would replace frequent leap seconds with infrequent larger corrections such as a leap hour, and a third would align Earth timekeeping with a NASA lunar standard.
- Engineers and major tech firms say leap seconds have caused outages and synchronization problems for networks, data centres and financial systems, which is a driving reason for removing the irregular one-second insertions.
- Some countries including Russia want more time to adapt because systems like GLONASS rely on leap-second insertion, and recent faster Earth rotation has raised the prospect of a disruptive 'negative leap second.'
- Leap seconds have been added 27 times since 1972 to keep atomic time and astronomical time aligned, and experts say abandoning them would leave clocks roughly 54 seconds ahead of solar time by 2100, requiring software and timestamp updates for astronomy and legacy systems.