[tz] Why is `Etc/UCT` not an alias of `Etc/UTC`?

Steve Allen sla at ucolick.org
Tue Mar 5 20:45:23 UTC 2019

On Tue 2019-03-05T12:00:59-0800 Alan Perry hath writ:
> My guess is that some people used the term "Universal Coordinated Time"
> before it got standardized to UTC.

The agreement that radio broadcast time signals would be coordinated
internationally based on cesium frequency standards originated during
tea time at the house of long time Greenwich Observatory Time Service
staff member H.M. Smith in 1959.  Initial coordination between UK and
US began in 1960, and full agreement on the mechanism was in place by
1961.  In 1961 the IAU and then in 1963 the CCIR recommended every
that time broadcast should be coordinated, but they did not give a
name, and many broadcasts were not coordinated until the 1970s.  The
first printed instance of a name was French T.U.C.  in 1965, but the
notion of coordination remained unknown outside of the time service

At the beginning of 1974 NBS station WWV started announcing as
Coordinated Universal Time.  In 1974 July the CCIR first used "UTC" in
Recommendation 460-1.  In 1975 June the CGPM used "UTC" in resolution
5.  In 1976 August the IAU recommended "UTC" to be used in all
languages.  In 1978 June CCIR Recommendation 536 recognized the
nomenclature from the 1975 CGPM and that "UTC" should be used in all

So there were 5 years without any abbreviation in print, 15 years
without any official designation of name, and after 20 years most of
the official documents were largely unavailable.  Even within the time
service community there are many variations on the nomenclature.

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