Des horloges atomiques au futur de la seconde - une école d'été sur l'UTC pour renforcer la mesure du temps
How does data from an atomic clock ultimately contribute to the international reference for time? And what skills do laboratories need to maintain accurate national time scales?
These questions brought 31 participants from 25 countries together for the BIPM–COOMET UTC Summer School, held at the Uzbek National Institute of Metrology (UzNIM) in Tashkent, Uzbekistan, from 28 to 30 September 2026. The programme combined tutorials with hands-on training in the techniques used to maintain national time scales and contribute to Coordinated Universal Time (UTC).
Participants and lecturers at the 2026 BIPM–COOMET UTC Summer School in Tashkent, Uzbekistan. Photo credit: UzNIM.
From the clock in the laboratory to UTC
Participants worked through the processes used to generate and compare national time scales and contribute to UTC, including:
- Clock analysis and time-scale generation: analysing clock data, identifying jumps and generating a national time scale UTC(k)
- Time comparisons: comparing clocks using Global Navigation Satellite Systems (GNSS) and processing data in the Common GNSS Generic Time Transfer Standard (CGGTTS) format.
- UTC contributions: understanding how laboratories contribute to the calculation of UTC through BIPM Circular T
- Time dissemination and emerging technologies: exploring Network Time Protocol (NTP) dissemination, automated monitoring, optical clocks and preparations for a possible future redefinition of the second
Using BIPM analysis tools, participants gained experience with techniques they could apply in their own laboratories and worked through technical questions with experts and colleagues from other institutes.
Participant feedback highlighted the value of direct access to experts, opportunities to discuss technical questions and exchanging knowledge with colleagues from other time laboratories.
Why this matters: The future of the second and UTC
At its 28th meeting in October 2026, the General Conference on Weights and Measures (CGPM) adopted resolutions addressing the future definition of the second and the technical actions needed to ensure the continuity of UTC.
As timekeeping technologies advance, national laboratories need the expertise to compare measurements, demonstrate traceability and contribute to the international timekeeping system. Training initiatives such as the UTC Summer School help develop these capabilities.
Explore the CGPM discussions
This Summer School forms part of the Consultative Committee for Time and Frequency (CCTF) programme of capacity building through resource sharing. It was jointly organized by the BIPM, UzNIM and COOMET TC4, with student participation supported by the IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society (IEEE UFFC).