--- title: "BIPM Announces Discontinuation of Leap Seconds to UTC" url: https://newscentral.site/bipm-announces-discontinuation-of-leap-seconds-to-utc/ language: en publisher: "News Central Site" section: "Technology" published: 2026-10-16T21:31:35.000Z updated: 2026-10-17T06:45:07.150Z id: 482c3afa-b592-4f1c-be4e-d62f2cf85838 source: "Wired https://www.wired.com/story/leap-second-is-abolished-bipm-says/" attribution: "Link to https://newscentral.site/bipm-announces-discontinuation-of-leap-seconds-to-utc/ and name News Central Site when you quote or summarize this story." --- # BIPM Announces Discontinuation of Leap Seconds to UTC The International Bureau of Weights and Measurements has announced that it will discontinue adding leap seconds to Coordinated Universal Time (UTC) effective May 2027. A long-standing debate in the metrological community has finally come to an end, with a major decision that will have far-reaching consequences for technology worldwide. The International Bureau of Weights and Measurements (BIPM) has announced that it will discontinue adding leap seconds to Coordinated Universal Time (UTC), effective May 2027. This means that the world's clocks will no longer be adjusted by a single second every few years to account for the Earth's slowing rotation. The reason for this change is due to the growing discrepancy between atomic time and UTC, which was introduced in 1972 to bridge the gap caused by the Earth's rotation losing pace. The culprit behind this slowdown is tidal friction, resulting from the moon's gravitational pull on our planet, as well as the molten core, oceans, and atmosphere affecting the Earth's spin rate. The decision to abolish leap seconds comes with a significant implication: it eliminates the possibility of a negative leap second, which could have caused disruptions in various time-sensitive systems. The BIPM has confirmed that 32 leap seconds have been added since 1972 to synchronize atomic clocks with UTC. To keep atomic clocks synchronized with astronomical time, a mechanism was introduced to account for the discrepancy between the two timekeeping systems - UTC and UT1. The process works by adding extra track time, or leap seconds, to UTC, ensuring it remains aligned with UT1. This is not done at regular intervals like leap years but through a more complex calculation that takes into account the average of hundreds of atomic clocks worldwide. The addition of leap seconds has been necessary 32 times since 1972, as confirmed by the BIPM. However, this process can be problematic for systems that rely on UTC, causing disruptions and requiring companies to adapt when leap seconds are introduced. Tech companies like Google and Meta have developed a workaround called "smear" methods, which helps them deal with the added complexity of leap seconds. This approach is used by Judah Levine, a fellow at the US National Institute of Standards and Technology, who notes that it allows for more flexibility in handling these adjustments. The introduction of a negative leap second was considered a possibility due to changes in Earth's rotational speed caused by climate change. As ice melts and shifts the planet's gravity, its rotation has picked up pace, potentially requiring a negative adjustment. This shift could have necessitated a negative leap second as early as 2029, according to a study published in Nature in 2024. The risk of having to implement this correction was deemed too great by those advocating for an end to the leap second altogether. The potential consequences of a negative leap second were considered more severe than those associated with positive adjustments. This concern was echoed by experts who pointed out that even after five decades, problems with leap seconds persisted. BIPM time department director Patrizia Tavella corroborated these concerns in an email, highlighting the need to reassess the use of leap seconds given their ongoing issues. The International System of Units (SI) has made a significant change by abolishing the leap second. This decision was made in conjunction with the anniversary of the Metre Convention signing on May 20, 1875. As part of this celebration, Metrology Day is being observed, providing a fitting occasion to mark the shift away from leap seconds. The removal of this timekeeping mechanism simplifies life for those who rely on it. The decision to eliminate leap seconds does not address the ongoing issue of atomic and astronomical time drifting apart over long periods. To mitigate this problem in the future, the BIPM has agreed to introduce a new time standard called a leap hour, although its implementation is still far off. --- Source: [Wired](https://www.wired.com/story/leap-second-is-abolished-bipm-says/) Published by News Central Site: https://newscentral.site/bipm-announces-discontinuation-of-leap-seconds-to-utc/