Urdu Report Desk
The international system used to keep the world’s clocks in sync with Earth’s rotation could undergo a major change, with scientists considering a proposal to eliminate leap seconds.
According to CNN, representatives of the International Bureau of Weights and Measures (BIPM) are considering a resolution that would remove leap seconds from the global time standard. The proposal is being discussed at a meeting in the Paris area, with representatives from 69 member countries expected to vote on the issue.
If approved, the proposed change could take effect in May 2027.
What Is a Leap Second?
The world uses two main methods to measure time. The first is based on Earth’s rotation, which determines the cycle of day and night. The second relies on atomic clocks, which measure time using the highly consistent natural oscillations of atoms.
Atomic clocks provide the precision needed to maintain Coordinated Universal Time (UTC), the international standard used by clocks and timekeeping systems worldwide.
However, Earth’s rotation is not perfectly constant. Factors including the Moon’s gravitational influence, changes inside Earth, ocean movements and the redistribution of water and ice can affect how quickly the planet rotates.
As a result, astronomical time based on Earth’s rotation can gradually drift away from the time measured by atomic clocks.
To keep the two systems sufficiently aligned, an additional second, known as a leap second, has occasionally been added to clocks.
Since 1972, a total of 27 leap seconds have been introduced to maintain this alignment.
Why Leap Seconds Cause Technical Problems
Although an extra second may seem insignificant in everyday life, it can create complications for modern digital infrastructure.
Computer networks, internet servers, telecommunications systems, power grids and data centres rely on precise and predictable timekeeping. Introducing an additional second can disrupt software that is not designed to handle the adjustment correctly.
Large websites, airline booking systems and data centres have experienced technical problems associated with leap-second adjustments, prompting major technology companies to support the elimination of the practice.
Removing leap seconds would allow atomic clocks to continue running without these periodic one-second changes, making timekeeping more predictable for technological systems.
International Body Considers the Proposal
The International Bureau of Weights and Measures, based near Paris in Versailles, plays a central role in establishing international measurement standards.
According to the report, representatives from its 69 member countries are expected to vote on the proposal to eliminate leap seconds.
The issue has been under discussion for several years. In 2022, member countries supported a resolution calling for a plan to phase out leap seconds by 2035 or earlier.
However, the proposal has faced concerns from countries and organisations whose navigation and timekeeping systems rely on different approaches.
Russia’s satellite navigation system uses leap seconds, while the United States’ GPS and the European Union’s Galileo systems follow different approaches to handling time.
The United Kingdom has also expressed concerns because of Greenwich’s historical role in global timekeeping. However, the report indicates that its position has since changed.
Could Scientists Eventually Need to Remove a Second?
Another factor complicating the debate is the changing speed of Earth’s rotation.
Although Earth’s rotation has generally slowed over long periods, the planet has rotated relatively quickly on some occasions in recent years.
If this trend continues, scientists may eventually need to subtract a second from clocks rather than add one. This adjustment is known as a negative leap second.
Such a change has never been implemented in global timekeeping, raising concerns about its potential impact on computer systems that record and process time continuously.
According to the BIPM, organisations operating critical technological systems are not yet fully prepared for this possibility. Updating these systems could also involve substantial costs.
What Happens If Leap Seconds Are Abolished?
Eliminating leap seconds would not suddenly change the length of a day or alter Earth’s rotation. Day and night would continue according to the planet’s natural movements.
Instead, the change would mean that global clocks would no longer receive periodic one-second adjustments to keep them closely aligned with Earth’s rotation.
Atomic clocks would continue measuring time steadily, even as their readings gradually diverged from time determined by the planet’s rotation.
Under the proposal, the maximum permitted difference between the two systems would be set at one hour.
Patrizia Tavella, head of the time department at the BIPM, said the difference could take more than 3,000 years to reach that limit.
Future generations would then have to decide whether to introduce a larger adjustment, which some experts have informally described as a "leap hour”, to bring the two systems back into alignment.
Why Some Experts Oppose Ending Leap Seconds
Not all specialists believe eliminating leap seconds is the best solution.
Marek Ziebart, a space geodesy expert at University College London, argues that the technical difficulties associated with leap seconds have been overstated.
He maintains that the existing system is functioning and preserves the connection between internationally measured time and Earth’s rotation.
According to this view, abolishing leap seconds would create its own technical challenges, requiring organisations to review, modify and retest software that currently accommodates the adjustments.
Changing the system could therefore impose additional costs and create new compatibility issues for organisations around the world.
Limited Impact on Everyday Life
Louise Devoy, senior curator at the Royal Observatory Greenwich, said most people would be unlikely to notice a direct difference in their daily lives if leap seconds were abolished.
People would continue their usual activities according to the familiar cycles of day and night. The main changes would occur behind the scenes, affecting how computers and other technological systems measure and synchronise time.
The debate ultimately centres on whether global timekeeping should prioritise maintaining a close connection with Earth’s natural rotation or provide a more stable and continuous time standard for modern technology.
The final outcome will depend on the international decision and the implementation measures adopted by the relevant authorities.
