[tz] [PATCH 2/3] Replace some zones with links when that doesn't lose non-LMT info.

Stephen Colebourne scolebourne at joda.org
Tue Sep 3 15:09:56 UTC 2013

On 3 September 2013 15:47, Paul Eggert <eggert at cs.ucla.edu> wrote:
> Brian Inglis wrote:
>> merging zones with different Standard Time
>> start date loses useful historical data
> That's not a problem for the proposed change,
> because in this particular case, no useful historical
> data are lost.  There is no real evidence that the
> start dates actually differed.  All we have is
> some guesswork from Shanks.  The Shanks data often
> contain guesswork, and the abovementioned
> transition dates from LMT are almost certainly
> part of that guesswork.
> The associated time zone abbreviations are also guesswork
> (in this case, my guesswork and not Shanks'),
> so they do not contain any useful historical data
> either.

Your long experience with the tzdb leads you to assert that these are
guesswork, therefore OK to delete. Unfortunately, the consumers of the
tzdb see the data as fact, and since the data has been there for many
years that simply reaffirms the "fact" status. I'd also suggest that
Shanks information has at least some degree of thought behind it,
certainly better than picking up the thoughts of some other location
that has always been under another jurisdiction.

I really wasn't joking when I suggested that pretty much no
refactoring is now possible. Its certainly the case that pretty much
every refactoring you can think of has some data loss.


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