According to an article published on October 15, 2026, by Scientific American, international metrology authorities have voted to end the leap second system, these periodic adjustments that keep official time in sync with Earth's rotation. This decision marks a new stage in how we measure time. Beyond scientific and technological issues, it invites a deeper reflection: how does our relationship with time evolve as we seek to measure it with ever greater precision?

Two ways to measure time

For millennia, human societies have based their measurement of time on the sky: the apparent movement of the Sun, the phases of the Moon, and the rotation of the Earth. Our days, seasons, and calendars have been organized around these natural phenomena.

With atomic clocks, we have gained a much more stable and reproducible measure of time. Time can now be defined based on the properties of atoms, with a precision that exceeds that allowed by the irregular rotation of our planet.

Since 1972, leap seconds have precisely served to maintain a link between these two references. Twenty-seven seconds have been added to official time, the last in December 2016. But these periodic corrections have become a difficulty for computer systems, telecommunications, and infrastructure that rely on continuous synchronization.

The international decision therefore favors the stability of atomic time over regularly correcting the official time to keep it aligned with the Earth's rotation.

In other words, we are increasingly dissociating the time we measure from the time that the Earth gives us to observe.

This is not the end of astronomical time, nor a change in the physical duration of a second. It is a redefinition of the rules that allow two references to coexist: one based on atomic physics, the other on the movements of the Earth.

What this decision reveals about our relationship with time

This is perhaps the most interesting aspect of this evolution. We are able to measure time with extraordinary precision, but this precision does not necessarily allow us to better understand what time represents in our lives.

An hour remains an hour on a clock. Yet, it is never experienced in the same way. It can seem endless while waiting for news, pass in an instant during a conversation or take on a completely different dimension when it accompanies an important moment.

Measured time is objective, quantifiable and reproducible. Lived time, on the other hand, depends on our attention, our emotions, our memory and our relationship with others.

In a society where everything speeds up, we often try to save time, to organize it, to optimize it. We evaluate our days based on what we have accomplished and the periods of our lives through the stages we have passed. Yet, some of the moments we value the most are precisely those that escape this logic: a meeting, a transmission, a gesture repeated for years, a conversation during which we do not see time pass.

Measurement helps us organize our existence. It is not enough to give it meaning.

Timekeeping, between precision and human experience

For the horological universe, this reflection takes on a particular dimension. Timekeeping is based on a historical tension between physical time, measured time, and lived time.

A mechanical watch translates the passage of time through a material movement. Its gears, its oscillator, and its escapement make visible a succession of physical phenomena. An atomic clock, on the other hand, defines time with a precision that traditional mechanics cannot achieve.

But a watch is not reduced to its precision. It can be an object of memory, a family heiritage, a witness to a life stage or the symbol of a meeting. It accompanies moments whose value does not depend on their duration or their measurement.

This is also what distinguishes timekeeping from a simple measuring instrument. It associates technical mastery with a cultural and personal dimension. It gives a tangible form to a reality that, by nature, escapes us.

Precision remains at the heart of its excellence, but it does not exhaust what makes a timepiece valuable. It can be sought for its performance, admired for its construction, or passed down for what it represents.

Learning to look at time differently

The decision to abandon leap seconds illustrates a broader evolution: as technology advances, our measurement tools gradually free themselves from the natural references that have long structured our perception of time.

However, our experience remains deeply connected to the Earth, to the cycles of light, to the seasons, and to the rhythm of our lives. We can perfect our instruments without ever reducing time to what they display.

Perhaps that is where the true lesson of this evolution lies. We now know how to measure time with a precision that would have been unimaginable for previous generations. But the question of what we do with it remains open.

Watchmaking invites us to hold together these two dimensions: the pursuit of precision and awareness of what gives value to a duration. It reminds us that time is not just a data to be mastered, but also an experience to be lived.

As science makes time more and more precise, are we losing something of the historical link between mechanical time, the Earth's movement, and our experience of the world? Or does this evolution, on the contrary, give us a new opportunity to reflect on what we choose to do with the time given to us?

Sources

Scientific American“Scientists Vote to End Leap Seconds, Redefining How the World Keeps Time” (15 October 2026).
https://www.scientificamerican.com/article/scientists-vote-to-end-leap-seconds-redefining-how-the-world-keeps-time/

International Bureau of Weights and Measures (BIPM)Resolutions of the 28th General Conference on Weights and Measures (CGPM).
https://www.bipm.org/

International Bureau of Weights and Measures (BIPM)Institutional information on Coordinated Universal Time (UTC) and leap seconds.
https://www.bipm.org/en/time-metrology