In recent years, the Earth has been spinning faster, shortening the length of our days by milliseconds. This trend was particularly noticeable in 2024, with July 5th marking the shortest day on record, 1.66 milliseconds less than the standard 86,400 seconds.
Experts from the International Earth Rotation and Reference Systems Service (IERS) and Timeanddate.com warn that these figures could be surpassed in 2025, especially around July 9th, July 22nd, and August 5th. This acceleration could significantly impact technologies that rely on precise time measurement, such as satellite navigation systems, global financial networks, and communication infrastructure.
To maintain synchronization between atomic time and the Earth's actual rotation, leap seconds are used. Typically, these adjustments involve adding an extra second when the planet slows down. However, for the first time, the possibility of a negative leap second is being discussed – subtracting a second from time to compensate for the Earth's accelerated rotation. While this subtle change won't affect daily life, it's crucial for experts and international organizations to closely monitor these variations and ensure the stability and accuracy of time-dependent systems.