List of meetings
Meetings and related documents
CCTF Working Group on Coordination of the Development of Advanced Time and Frequency Transfer Techniques
Guidance documents on the CIPM MRA
The Consultative Committee for the Definition of the Second (CCDS) was set up in 1956. Its name was changed to Consultative Committee for Time and Frequency (CCTF) by the CIPM in 1997.
Present activities concern matters related to the definition and realization of the second, establishment and diffusion of International Atomic Time (TAI) and Coordinated Universal Time (UTC), and advice to the CIPM on matters related to time and time scales.
Record number of frequency standards contribute to International Atomic Time
In November 2021 a new record of sixteen different frequency standards operated by eleven laboratories contributed to the accuracy of International Atomic Time TAI. They include three recently developed optical lattice clocks. This achievement is another step towards a future redefinition of the second.