Keep up to date with plans for the redefinition of the second

The CCTF has prepared a webpage that will be updated regularly with information on the redefinition.

BIPM Circular T: updated format and new information

The changes will be introduced from Circular T number 437 in June 2024.

The BIPM announces technical updates to Circular T

The changes shall be implemented starting from Circular T 437 in June 2024.

New CCL-CCTF Application Programming Interface prototype web service is now available

The mises en pratique for the metre and the second are now machine-readable.

First official use of Galileo measurements in the computation of Coordinated Universal Time