IERS Confirms No Leap Second Will Occur at End of December 2026

No leap second will be introduced at the end of December 2026

The International Earth Rotation and Reference Systems Service has officially announced that no leap second will be added to Coordinated Universal Time at the end of December 2026. This decision keeps the difference between UTC and International Atomic Time at minus 37 seconds. The bulletin confirms that time adjustments will continue to be monitored every six months based on the Earth's rotation.

No leap second will be introduced at the end of December 2026.
  1. doctoboggan

    What causes the unpredictability in this? I would have guessed we have earth's rotation and orbit down to many decimals. Does geological activity, weather, or something else cause rotation speed differences that we just can't predict?

  2. ChrisArchitect

    Notice they only said leap second.

    Meanwhile....

    International timekeepers to vote on changing the leap second to a leap hour

    https://www.scientificamerican.com/article/international-tim... (https://archive.ph/GnQUj https://news.ycombinator.com/item?id=48842329)

  3. AbstractH24

    ELI5: How does this impact UNIX timestamps? Particularly for things that are in maintenance mode or otherwise minimally maintained.

    Nothing I do requires this level of precision, but certainly there are things that do.

  4. usr1106

    Isn't this anti-news? I vaguely remember they have stopped introducing leap seconds until further notice because they cause too much trouble with today's computing systems. On my phone now and did not research it, as I say vaguely remember. Now we are 37 seconds off. Nobody of us will have to worry that Christmas is around Easter time. We can leave that problem to future generations much more responsibly than many other problems.

    That the notice comes every 6 months is just to meet the letter of the original international treaty.

  5. bombcar

    "To authorities responsible for the measurement and distribution of time" is just the best preamble ever.

  6. KboPAacDA3

    If the UTC-TAI offset remains at -37s, then it also means the UTC-GPS offset remains at -18s. TAI and GPS have a constant 19s offset from each system.

  7. srean

    What happens to systems such as Spanner under these circumstances?

    Is it a headache or a non-issue

  8. delichon

    Hear me out. We can just mount jet engines along the equator and rotate them 180 to gain or lose time. And then connect them to my snooze button.

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