Re: [Tzdist] [tz] Timezone in Brazil

Lester Caine <lester@lsces.co.uk> Sun, 11 October 2015 22:03 UTC

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To: Paul Eggert <eggert@cs.ucla.edu>
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From: Lester Caine <lester@lsces.co.uk>
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Date: Sun, 11 Oct 2015 23:02:54 +0100
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Subject: Re: [Tzdist] [tz] Timezone in Brazil
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On 11/10/15 22:12, Paul Eggert wrote:
> Lester Caine wrote:
>> tzdb should only be published with a
>> 1970 start date and anything prior to that is unreliable
> 
> No, many tzdata entries before 1970 are quite reliable.  True, tzdata
> entries tend to become less reliable the further back one goes in time,
> but this is merely a tendency.  For example, the data for England in
> 1915 is far more reliable than the data for Baja California state in 2015.

'MANY' ... but there is data in backzone which conflicts with the
non-backzone version despite being verified and relating to the very
material I am working with. Additionally material relating to local
standard times in the UK is well authenticated, but is not easy to
distinguish when all that is available is a 'Europe/London' rule set.
The only way to handle things currently IS to say "don't rely on your
computers offsets for any material prior to 1970" ... it may or may not
be correct.

-- 
Lester Caine - G8HFL
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