[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 

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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