Media Centre • Press Release
Assembly defers decision to eliminate the leap second
Geneva, 19 January 2012 – The ITU Radiocommunication
Assembly has reached an important decision to defer the development of a
continuous time standard in order to address the concerns of countries that use
the current system of the leap second in Coordinated Universal Time (UTC).
The decision has been reached to ensure that all the technical options have
been fully addressed in further studies related to the issue. These studies will
involve further discussions within the ITU membership and with other
organizations that have an interest in this matter and will be referred to the
next Radiocommunication Assembly and World Radiocommunication Conference
scheduled for 2015.
Adjustments made in one second steps, known as ‘leap seconds’, have been
implemented since 1972 to compensate for variations in the speed of the earth’s
rotation within the framework of Coordinated Universal Time (UTC).
UTC is defined by ITU’s Radiocommunication Sector and is maintained by the
International Bureau of Weights and Measures (BIPM) in cooperation with the
International Earth Rotation and Reference Systems Service (IERS). Measurements
from timing centres around the world are used in the determination of UTC, which
is adjusted to within 0.9 seconds of Earth rotation time (UT1) by
IERS-determined values of the Earth’s rotation.
The suppression of the leap second would make continuous time scale available
for all the modern electronic navigation and computerized systems to operate
with and eliminate the need for specialized ad hoc time systems. This however
may have social and legal consequences when the accumulated difference between
UT1 – Earth rotation time – would reach a perceivable level (2 to 3 minutes in
2100 and about 30 minutes in 2700).
ITU Secretary-General Hamadoun Touré considered the decision taken by the
Radiocommunication Assembly will ensure that all stakeholders have been
adequately associated with a step which will clearly influence our future.
For more information, please contact:
Chief, Media Relations
and Public Information
Media Accreditation enquiries to the Radiocommunication Assembly and
World Radiocommunication Conference:
Videos are available on
YouTube with broadcast quality footage on demand.