[tz] Pre-1970 data

Philip Paeps philip at trouble.is
Fri Nov 5 05:11:26 UTC 2021

On 2021-11-05 12:17:34 (+0800), Brian Park via tz wrote:
> I get the impression that this debate is caused by the existence of 2
> different schools of thought: [...]
> I want to suggest that it may be possible for these 2 views to 
> coexist.

They de facto coexist right now.  The overwhelming majority of the data 
are descriptive.  Only recent efforts have made some of the post-1970 
data appear more prescriptive.

> We
> could create a new file, e.g. call it 'countryzone', which contains a 
> set
> of Links organized in a hierarchical tree by country, pointing to the 
> Core
> zones.

I strongly believe we should continue to carefully avoid attempting to 
group data by country.  [I would even avoid using the word "country" 
wherever possible.]

> For the pre-1970 data, it is my understanding that the 'backzone' file
> contains Zone records which should replace ONLY the LinkMerged records
> found in the other files. I propose that all LinkMerged records be
> extracted into a separate file (let's call it 'mergedzone') so that 
> there
> is a clear symmetry between 'backzone' and 'mergedzone', which allows 
> them
> to be substituted for each other. The dependency diagram looks 
> something
> like this:

As I've suggested before in another thread, I think we should consider 
undoing the split into backzone.  I really liked Stephen's phrasing 
earlier in this thread: acceptably accurate, not outrageously wrong.  We 
started moving data to backzone to limit the scope of 'active' 
maintenance to post-1970 data.  That artificial split led us towards a 
more prescriptive worldview.  It seems clear that prescriptive simply 
does not work for a real world with people on it.

> If there is any chance that this will result in being able to type
> "Canada/Toronto" instead of "America/Toronto", that would resolve an
> annoyance that has lasted some 30-35 years.

In this context, America refers to the landmass, not to the political 
entity occupying a large chunk of it.  [Canada/Eastern etc moved to 
backward around 1993, as far as I can tell.]

Trying to group by country would only lead to (more) divisive arguments. 
  I do support the notion that we should have at least one time zone 
identifier per ISO code though (whether or not that code refers to a 


Philip Paeps
Senior Reality Engineer
Alternative Enterprises

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