INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS)

SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE

SERVICE DE LA ROTATION TERRESTRE DE L'IERS<br>OBSERVATOIRE DE PARIS<br>61, Av. de l'Observatoire 75014 PARIS (France)<br>Tel. : +33 1 40 51 23 35<br>e-mail : services.iers@obspm.fr<br>http://hpiers.obspm.fr/eop-pc

Paris, 06 July 2026

Bulletin C 72

To authorities responsible<br>for the measurement and<br>distribution of time

INFORMATION ON UTC - TAI

NO leap second will be introduced at the end of December 2026.<br>The difference between Coordinated Universal Time UTC and the<br>International Atomic Time TAI is :

from 2017 January 1, 0h UTC, until further notice : UTC-TAI = -37 s

Leap seconds can be introduced in UTC at the end of the months of December<br>or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every<br>six months, either to announce a time step in UTC, or to confirm that there<br>will be no time step at the next possible date.

Christian BIZOUARD<br>Director<br>Earth Orientation Center of IERS<br>Observatoire de Paris, France