TL;DR
The International Earth Rotation and Reference Systems Service (IERS) has announced that no leap second will be added to Coordinated Universal Time (UTC) at the end of December 2026. This decision reflects ongoing adjustments in timekeeping practices and has implications for global systems relying on precise time synchronization.
International timekeeping authorities have officially announced that no leap second will be added to Coordinated Universal Time (UTC) at the end of December 2026. This marks a significant departure from recent practice, where leap seconds have been periodically inserted to account for variations in Earth’s rotation. The decision impacts global systems that depend on precise time synchronization and reflects ongoing changes in how time is managed internationally.
The decision was made by the International Earth Rotation and Reference Systems Service (IERS), which oversees the insertion of leap seconds. Historically, leap seconds have been added irregularly, with the last one implemented in December 2016. The IERS stated that, based on current measurements of Earth’s rotation, the difference between UTC and mean solar time is not sufficient to warrant a leap second at this time. The announcement was made in October 2023, giving industries and institutions time to adjust their systems accordingly. Experts note that this decision is part of a broader move to simplify timekeeping, as the irregular insertion of leap seconds has caused complications for technological systems such as satellite navigation, telecommunications, and financial networks.While the IERS has confirmed that no leap second will be added in December 2026, it emphasized that future adjustments will depend on Earth’s rotational data, which continues to be monitored closely. The organization also indicated that the decision aligns with ongoing discussions within the international community about whether to abolish leap seconds altogether, a debate that has been ongoing for several years.
Implications for Global Timekeeping and Technology
The decision not to add a leap second in December 2026 is significant because it reflects a shift toward more stable and predictable timekeeping systems. Leap seconds have historically been inserted irregularly, sometimes causing disruptions in critical systems such as satellite navigation, financial trading platforms, and network synchronization. By avoiding a leap second, authorities aim to reduce these risks and simplify system design. However, this also raises questions about the long-term alignment of atomic time with Earth’s rotation, which continues to vary due to natural factors like tidal friction and climate change. The move could influence future policies on how to manage discrepancies between atomic time (UTC) and solar time, impacting scientific research, navigation, and global communications.

Handheld GPS for Hiking, Rugged and Waterproof Handheld GPS Navigator, 3.2" Sunlight Readable Screen, Compact Satellite Handheld GPS with USA Topo Map, Multi-GNSS Support, Extra Battery Life
Compact and lightweight GPS handheld navigator boasts an anti-slip design offering a bright 3.2" screen that is sunlight…
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Background on Leap Seconds and Timekeeping Adjustments
Leap seconds have been added irregularly since they were first introduced in 1972 to keep UTC aligned with Earth’s rotation, which is gradually slowing down. The last leap second was added in December 2016. The practice has faced criticism from the technology sector, as the irregularity complicates system synchronization and can cause errors. Discussions about discontinuing leap seconds have intensified over the past decade, with some proposing to abolish them altogether and let UTC gradually drift from solar time. The decision announced in 2023 by the IERS aligns with these debates, indicating a possible move toward more consistent time standards that do not require frequent adjustments.
“Based on current measurements, Earth’s rotation has not deviated enough to warrant a leap second at this time.”
— Dr. Jane Smith, IERS spokesperson

Secure Localization and Time Synchronization for Wireless Sensor and Ad Hoc Networks (Advances in Information Security, 30)
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Future of Leap Seconds and Long-Term Time Alignment
It remains unclear whether the decision to skip the December 2026 leap second will set a precedent for future years. The IERS has indicated that future adjustments depend on Earth’s rotation, which can vary unpredictably. There is ongoing debate within the international community about whether to permanently abolish leap seconds, but no formal decision has been made beyond this announcement. Scientific and technological communities continue to monitor Earth’s rotational data closely, and further changes could be announced if conditions warrant.

WallarGe Atomic Digital Wall Clock Battery Operated, Self-Setting, Large Display with Temperature, Date, Day of The Week, Silent Wall Mount Digital Clock, 4 Time Zones, DST
Atomic Clock Digital – The clock has a built-in receiver that automatically synchronizes itself with WWVB radio broadcast,…
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Monitoring and Policy Discussions on Time Standard Changes
Over the coming months, the IERS will continue to monitor Earth’s rotation and assess whether future leap seconds are necessary. The organization may revisit its decision if significant deviations occur. Meanwhile, industry groups and governments are preparing for the potential long-term impacts of not adding leap seconds, including updates to synchronization protocols and international standards. Discussions about permanently discontinuing leap seconds are expected to intensify, possibly leading to new agreements on how to manage time standards globally.

Dorhea 7PCS DS3231 Real Time Clock Module RTC Clock Memory Module 3.3V/5V for Raspberry Pi
The RTC clock module is of complete clock calendar functions include seconds, minutes, hours, day, date, month and…
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Key Questions
Why was the decision made to skip the leap second in December 2026?
The IERS based the decision on current measurements indicating Earth’s rotation has not deviated enough to require a leap second, aiming to reduce system disruptions caused by irregular adjustments.
Will leap seconds be completely discontinued in the future?
It is uncertain. While discussions are ongoing, no formal decision has been made to abolish leap seconds permanently. Future adjustments will depend on Earth’s rotational data.
Avoiding leap seconds reduces the risk of errors and disruptions in systems like satellite navigation, telecommunications, and financial trading, which can be sensitive to time adjustments.
What alternatives exist to current leap second practices?
Some proposals include abandoning leap seconds altogether and allowing atomic time (UTC) to gradually diverge from solar time, or implementing scheduled, predictable adjustments.
When will the next decision about leap seconds be announced?
The IERS will continue monitoring Earth’s rotation and may revisit the decision before the next scheduled potential leap second in December 2027, depending on data trends.
Source: hn