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

Alan Perry alanp at snowmoose.com
Tue Mar 5 21:38:57 UTC 2019

On 3/5/19 12:45 PM, Steve Allen wrote:
> 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
> community.
> 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
> languages.
> 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.
Understood, but the question concerned "UCT". My comment was in response 
to a suggestion that it was a misspelling.

If it were simply a misspelling, then it seems like it should be an 
alias for UTC. But it isn't.

Then again, even if some people used "universal coordinated time" 
instead of "coordinated universal time" (like WWV says), it seems like 
it would still be an alias for UTC. So, it comes back to why isn't it an 
alias for UTC.


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