On July 10, 2025, Earth set a new record by shortening the length of a day by 1.36 milliseconds from the usual 24 hours. This is the shortest day since modern observations began. The data was recorded by the International Earth Rotation Service (IERS) and the US Naval Observatory, and the news was announced by CNN.
Similar phenomena are expected to recur in the coming days — in particular, July 22 and August 5 are also expected to be shorter than normal. The reasons for this are the gravitational influence of the Moon, seasonal changes in the atmosphere, geophysical processes in the planet's liquid core, and the effects of climate change.
Why is this important for the world?
Although the loss of a millisecond is almost imperceptible in everyday life, it is critically important for technology. Coordinated Universal Time (UTC), which is the basis for satellite navigation systems, financial transactions, telecommunications networks and data centers, depends on ultra-precise atomic clocks.
Since 1972, 27 leap seconds have been introduced to compensate for the slowing down of the planet's rotation. But now the situation is different: the Earth is accelerating. This could lead to a historic event - the first ever subtraction of a "negative second". Experts warn that such an operation could cause serious technical failures - similar to the "Year 2000 problem".
The role of climate in changing the rhythm of the planet
Climate change also affects the speed of Earth's rotation. The melting of glaciers in Greenland and Antarctica redistributes the planet's mass, which in turn can slow down the rotation slightly. It is thanks to this effect that the question of subtracting a second no longer arises today.
Although we don't physically feel these changes, the world is gradually preparing for technological challenges. Scientific teams in different countries are monitoring changes in day length and working on how to adapt global systems to the new conditions.
