EEM/
Articles/
2511002345
  • Open Access
  • Letter
Economic and Operational Implications of the Leap Second and its Cancellation
  • Alessandro De Angelis 1,2,*,   
  • Bernardo Giulio Moretti 1

Received: 12 Nov 2025 | Revised: 19 Nov 2025 | Accepted: 20 Nov 2025 | Published: 24 Nov 2025

Abstract

Leap seconds are one-second adjustments added to Coordinated Universal Time (UTC) to keep it within ±0.9 s of Earth’s rotational time (UT1), i.e., to synchronize atomic time with astronomical time. Since 1972 there have been 27 positive insertions, the last on 31 December 2016. In November 2022 the General Conference on Weights and Measures (CGPM) adopted a path to phase out future leap seconds by or before 2035, moving toward a continuous UTC. This article consolidates documented operational incidents and presents a back-of-the-envelope economic assessment of leap-second events. We find that a single leap second plausibly exposes the global economy from the low tens of millions up to about USD 100 million in direct disruptions, with tail risks concentrated in finance, aviation, and large-scale internet platforms.Removing the leap second reduces coordination burden and eliminates a rare but brittle failure mode—especially salient given the prospect of a possible first-ever negative leap second.

References 

  • 1.

    IERS. Bulletin C Page (TAI−UTC = 37 s; Announcements). 2025. Available online: https://www.iers.org/IERS/EN/Publications/Bulletins/bulletins.html (accessed on 10 July 2025).

  • 2.

    IERS. Bulletin C 52: Positive Leap Second at End of December 2016. 2016. Available online: https://www.iers.org/IERS/EN/Publications/Bulletins/bulletins.html (accessed on 10 July 2025).

  • 3.
    Nelson, R.A.; McCarthy, D.D.; Malys, S.; et al. The leap second: its history and possible future. Metrologia 2001, 38, 509–529.
  • 4.

    BIPM/CGPM. Resolution 4 of the 27th CGPM: On the Future of the UTC Timescale. 2022. Available online: https://www.bipm.org/en/cgpm-2022/resolution-4 (accessed on 10 July 2025).

  • 5.
    BIPM. WRC-23 Recognizes CGPM Resolutions 2 (2018) and 4 (2022). 2023. Available online: https://www.bipm.org/en/-/2023-12-12-wrc-dubai (accessed on 10 July 2025).
  • 6.
    Gibney, E. The leap second’s time is up: World votes to stop pausing clocks. Nature 2022, 612, 18.
  • 7.

    Meta Engineering. It’s Time to Leave the Leap Second in the Past. 2022. Available online: https://engineering.fb.com/2022/07/25/production-engineering/its-time-to-leave-the-leap-second-in-the-past/ (accessed on 13 July 2025).

  • 8.

    Crozier, R. Qantas Outage Pinpointed on Leap Second Linux Bug. iTnews 2012. Available online: https://www.itnews.com.au/news/qantas-outage-pinpointed-on-leap-second-linux-bug-307379 (accessed on 11 July 2025).

  • 9.

    Hamilton, D. Leap Second Bug Snarls Air Travel in Australia. Data Center Knowledge 2012. Available online: https://www.datacenterknowledge.com/business/leap-second-bug-snarls-air-travel-in-australia (accessed on 10 July 2025).

  • 10.

    Metz, C. LeapSecondCauses Sporadic Outages Across the Internet. WIRED 2015. Available online: https://www.wired.com/2015/07/leap-second-causes-sporadic-outages-across-internet/ (accessed on 10 July 2025).

  • 11.
    CMEGroup. Electronic Trading Advisory—Leap Second (15 June 2015). Available online: https://www.cmegroup.com/tools-information/lookups/advisories/electronic-trading/20150615.html (accessed on 10 July 2025).
  • 12.
    CMEGroup. Clearing Advisory—Leap Second Event (Chadv15-132). 2015. Available online: https://www.cmegroup.com/tools-information/lookups/advisories/clearing/Chadv15-132.html (accessed on 11 July 2025).
  • 13.

    London Stock Exchange Group—Turquoise. UTC Leap Second Information (Technical Notice). 2015. Available online: https://docs.londonstockexchange.com/sites/default/files/documents/TN Turquoise UTC Leap Second June 2015.pdf (accessed on 12 July 2025).

  • 14.

    NIST. Best Practices for Leap Second Event Occurring on 30 June 2015. 2015. Available online: https://www.nist.gov/system/files/documents/2016/09/28/best-practices-leap-second-june30-2015.pdf (accessed on 15 July 2025).

  • 15.

    Ponemon Institute & Emerson/Vertiv. Cost of Data Center Outages—Research Report. 2016. Available online: https://www.vertiv.com/globalassets/documents/reports/2016-cost-of-data-center-outages-11-11 51190 1.pdf (accessed on 11 July 2025).

  • 16.
    Airlines for America. U.S. Passenger Carrier Delay Costs (2024). 2025. Available online: https://www.airlines.org/dataset/u-s-passenger-carrier-delay-costs/ (accessed on 20 June 2025).
  • 17.
    Agnew, D.C. A global timekeeping problem postponed by global warming. Nature 2024, 628, 333–336.
  • 18.

    Tavella, P.; Mitrovica, J.X. Melting ice solves leap-second problem—For now. Nature 2024, 273–274. Available online: https://www.nature.com/articles/d41586-024-00850-x (accessed on 20 June 2025).

Share this article:
Download PDF
Issue
Volume 1, Issue 1
How to Cite
De Angelis, A.; Moretti, B. G. Economic and Operational Implications of the Leap Second and its Cancellation. Ecological Economics and Management 2025, 1 (1), 5.
RIS
BibTex
Copyright & License
article copyright Image
Copyright (c) 2025 by the authors.