[fitswcs] History question about "UTC"

[Steve Allen]

On Wed 2007-03-28T15:17:00 -0400, Don Wells hath writ:
>       The International Telecommunication Union wanted
>       Coordinated Universal Time to have a single abbreviation
>       for all languages. English speakers and French speakers
>       each wanted the initials of their respective languages'
>       terms to be used internationally: "CUT" for "coordinated
>       universal time" and "TUC" for "temps universel
>       coordonne�". This resulted in the final compromise of
>       using UTC.
>
> That sounds vaguely urban-legendish.  How based in fact is it?

Well, most of what I know is at
http://www.ucolick.org/~sla/leapsecs/timescales.html
but I also have in hand copies of the relevant pages of the documents
from the IAU general assemblies.

I am pretty certain that CCIR Recommendation 374 was the original
specification for the radio broadcasts of atomically-regulated time
and that it was first published in 1963.  I do not have access to
this recommendation.

The proceedings of the IAU's XIIIth General Assembly in Prague in 1967
on August 24/26 imply that it was within the previous triennium that
the term UTC was coined.  In section 6.1 of the document "The leap
second: its history and possible future" (Nelson et al., Metrologia
v38, #6, pp509-529, 2001)
(and I reiterate here that EVERYONE should read this document)
we read that the IAU "approved" the name UTC.

In the proceedings of that IAU meeting, resolution 3 on page 181
indicates that the name UTC seems to have been attached to the
broadcasts by the first revision of CCIR 374, namely Recommendation
374-1, CCIR Documents of the XIth Plenary Assembly, Osly 1966, Volume
III, p.  281, 282.  In the same sentence it states merely that UTC
"soit universellement etendue".  I take this resolution as being no
stronger than recognition of the CCIR as defining the name, not as
meaning the name was actually "approved" by the IAU.  The only people
who could say otherwise as of now are probably Guinot and Kovalevsky,
and I suspect that some of those now dead would disagree with whatever
they might say.

It is clear, however, that the initials UTC (then typically rendered
U.T.C.  in English texts and T.U.C.  in French) had been in use for
some time before the 1967 IAU meeting.  That they were used in the
same paragraphs as U.T.  (and T.U.), U.T.0, U.T.2, E.T., E.T.1, E.T.0,
A.T.  (and T.A.), S.A.T., U.T.C, etc.

The notions for UT0, UT1, and UT2 were approved by the IAU in 1955,
but I know of no written record for their actual names (and in French
they tended to be written with the ordering TU0, TU1, TU2).
I cannot recall where I have read that the names were probably coined
by Markowitz as chair of IAU 31 while working the implementation out
with the folks then at BIH.  The Stoykos are dead, Guinot has written
several documents about this, and for further oral histories I would
aldo direct historians at Seidelmann and McCarthy.

The principal effect of CCIR 374-1 may have been to reinforce the
rolling of the typographical snowball for the dropping of the periods
in the abbreviations and the adoption of a single ordering independent
of language.  In the 1970 IAU documents the ordering was consistent
everywhere, and some authors still used periods.  In the 1973 IAU
documents the periods were all gone.

So I don't have any facts.  I can't say what the CCIR were thinking in
1966.  I would love to see the actual document along with proceedings,
and interviews of anyone who was there, but I suspect they were
following the lead of Markowitz when he helped coin UT0, UT1, and UT2
about a decade earlier.

--
Steve Allen                 <sla at ucolick.org>                WGS-84 (GPS)
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