Roadmap to the redefinition of the second

The CCTF is currently working towards an update of the definition of the second, in accordance with the significant improvements in atomic clock designs that have occured in the recent years.

This web page collates some of the general and publicly accessible information associated with the process.

The time and frequency community is highly engaged in the long journey that will eventually lead to the redefinition of the second, possibly in 2030. We will update and add content to this page in the coming years. Please revisit this page regularly to stay up to date.