[tz] [PATCH] tzdata: Asia/Ha_Noi: Add new timezone
Paul Eggert
eggert at cs.ucla.edu
Sat Oct 4 18:09:03 UTC 2014
Brian Inglis wrote:
> On 01.07.1906
> When completed construction Observatory Phu Lien, Indochina government decree
> dated 09.06.1906 (Official Gazette dated 18.06.1906 Indochina) fixed now legal
> for all countries of Indochina under the meridian passing through Phu Lien
> (104°17'17" east of Paris) from 0 hours on 01.07.1906.
Yes, thanks, I'm working my way through that web page. For that paragraph, I
assume "east of Paris" means east of Paris Mean Time, which was legally 00:09:21
east of Greenwich, and since 104°17′17″ works out to 06:57:09.1333..., that
would make Phù Liễn Mean Time legally 07:06:30.1333.... An alternate
interpretation would be that it refers to François Arago's definition of the
Paris Meridian; in that case Phù Liễn Mean Time would be the temporal equivalent
of 2°20′14.03″ + 104°17′17″ east, which would be 07:06:29.33333.... Luckily
both values round to 07:06:30, so we can use this rounded value under either
interpretation.
By the way, if Google Maps and <http://kml.inovmapping.com/Ph-Lin-Observatory>
are to believed the observatory is a bit east of both values, at roughly
07:06:31; but perhaps they moved the observatory since 1906, and anyway the
legal definition is close enough.
I assume the abbreviation should be PLMT for Phù Liễn Mean Time.
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