No leap second will be introduced at the end of December 2026

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

OBSERVATOIRE DE PARIS

61, Av. de l'Observatoire 75014 PARIS (France)

Tel. : +33 1 40 51 23 35

e-mail : services.iers@obspm.fr

http://hpiers.obspm.fr/eop-pc

Paris, 06 July 2026

Bulletin C 72

To authorities responsible

for the measurement and

distribution of time

INFORMATION ON UTC - TAI

NO leap second will be introduced at the end of December 2026.

The difference between Coordinated Universal Time UTC and the

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

or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every

six months, either to announce a time step in UTC, or to confirm that there

will be no time step at the next possible date.

Christian BIZOUARD

Director

Earth Orientation Center of IERS

Observatoire de Paris, France