[LEAPSECS] Footnote about CCITT and UTC

Poul-Henning Kamp phk at phk.freebsd.dk
Fri Dec 12 13:24:41 EST 2008

In message <20081212.091847.-653353160.imp at bsdimp.com>, "M. Warner Losh" writes


>In message: <10832.1229096666 at critter.freebsd.dk>

> "Poul-Henning Kamp" <phk at phk.freebsd.dk> writes:


>: As part of some research on a different topic, I came across a

>: summary of the 1980 plenary meeting of CCITT, where appearantly the

>: CCITT formally decided to switch from GMT to UTC.


>that would make interesting reading. Is it available?

I checked and I think this may be referring to CCITT recommendation

Recommendation B.11
Fascicle I.3 - Rec. B.11
(Geneva, 1980)



(a) that according to CCIR Recommendation 460-3 all
standard-frequency and time-signal emissions should conform
to Coordinated Universal Time (UTC);
(b) that since 1972 UTC has been available as a worldwide
time reference;
(c) that in 1975 the General Conference of Weights and
Measures (CGPM) recommended the use of UTC as the basis of
civil time;
(d) that other scientific organizations, particularly
the International Astronomical Union (IAU) and the International
Union of Radio Science (URSI) have recommended the general
use of UTC;
(e) that UTC enables the time of events to be determined
with an uncertainty of 1 µs;
(f) that according to CCIR Recommendation 536 and in
accordance with the Recommendation of the General Conference
of Weights and Measures the designation UTC is to be used
in all languages;
(g) that the World Administrative Radio Conference
(Geneva, 1979) has decided that UTC shall be used in
international radiocommunication activities;
(h) that in accordance with Appendix 2 to the Telegraph
and Telephone Regulations, Geneva, 1973 (relating to
reciprocal exchange of information through the medium of
the General Secretariat) Resolution No. 1 of these Regulations
recommends Administrations inter alia to inform the
Secretary-General of the legal time they apply.

unanimously recommends

that UTC should be used to designate the time in all other
international telecommunication activities (including
operational information) and in all service documents of
the International Telecommunication Union.

None of that is really interesting, except the very late date...


PS: According to Wikipedia, ISO 31-1 defines a day as 86400 seconds,
anybody here who can verify if this is really the original text ?

Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

More information about the LEAPSECS mailing list