Time Lords kill leap seconds, which they warn could become the new Y2K bug
Developed over time first seen 1 hour ago
The General Conference on Weights and Measures has voted to stop adding leap seconds to Coordinated Universal Time, citing the risk of disruption to connected devices and critical infrastructure. The change addresses concerns that systems may struggle to handle a leap second, particularly a negative one, and could require remediation on a scale comparable with the Y2K preparations.
Leap seconds have been used to keep UTC aligned with UT1, which reflects variations in Earth’s rotation. The conference said preparing industries for a negative leap second could require investment similar to that made for the millennium bug, whose global remediation cost is estimated in the article at $300 billion to $600 billion. It also warned that inconsistent methods for handling leap seconds can cause timing differences across systems; poorly updateable IoT devices could fail to handle the change and disrupt services such as network connections.
- Time standards body votes to stop adding leap seconds.
- It warns that connected devices could malfunction.
- A negative leap second could prompt Y2K-scale preparations.
Full account
An international body responsible for measurement standards has voted to bring the practice of adding leap seconds to Coordinated Universal Time (UTC) to an end. The decision by the General Conference on Weights and Measures (CGPM) reflects concern that occasional changes to the clock could disrupt the growing number of connected systems that depend on a shared time. Its resolution singles out internet-connected devices, smart grids and other distributed services, where a change of just one second may be difficult to apply consistently.
Leap seconds were introduced to keep UTC close to UT1, a measure of time based on the Earth’s rotation. Atomic clocks provide a steady reference, but the planet does not turn at a perfectly constant rate. When its rotation has fallen sufficiently behind atomic time, an extra second has been inserted to narrow the gap. More recently, a slight speeding up of the Earth’s rotation has raised the possibility of removing a second instead. That would be a first, and the CGPM warned that critical infrastructure is largely unprepared for it.
The resolution also points to a problem that already exists: large technology providers use different methods to soften the effect of a leap second on their systems. Those methods can leave services temporarily out of step with one another, undermining the consistency that a common time standard is meant to provide. As connected devices and automated services become more widespread, the task of updating them all becomes harder. The CGPM estimated that preparing industries dependent on synchronised time for a negative leap second could require investment on a scale comparable to preparations for the millennium bug.
The vote marks a shift in how timekeepers balance the Earth’s rotation against the needs of modern technology. Keeping civil time closely aligned with the planet’s spin has practical value, but each adjustment introduces a potential fault into networks that expect time to advance predictably. The CGPM’s decision reflects its judgement that the risks of continuing with leap seconds, particularly if a second ever has to be removed, now outweigh the benefit of maintaining that close alignment through repeated adjustments.
Where outlets differ
The two supplied reports contain the same text, so they provide no distinct outlet perspectives to compare. Both emphasise the risks to connected devices, the unprecedented possibility of a negative leap second and the potential cost of preparation. The supplied text ends mid-sentence, so it does not establish the full terms or timetable of the decision.