[tz] Dealing with Pre-1970 Data

Stephen Colebourne scolebourne at joda.org
Fri Aug 30 09:43:40 UTC 2013

On 30 August 2013 03:44, David Patte ₯ <dpatte at relativedata.com> wrote:
> My own preference would be that historical (and perhaps all tz data) be
> given a numberic identifier, not a 'America/Someplace' name, for the
> populated areas in question. A good source of geographic identifiers already
> available is the geonames database. The tz data for Montreal could be
> identified by the geonames number for Montreal, and the tz data for Toronto
> associated with the geoname number for Toronto.
> Then, to build regions, since all geonames records already have a field for
> the tz region, these could reflect the numeric identifier of the tz
> recommended region for each location. For example, Ottawa, in the geonames
> database would refer to the numeric identifier of Toronto instead of
> 'America/Toronto', until sometime decides to add historical data for
> Ottawa's own tz history, at which point it would adopt the identifier for
> Ottawa.

For the record, such a numeric system would be unacceptable to my
user-base of developers, who need to include time-zone strings in
configuation systems, initialization code and test cases. The IDs we
have are relatively stable and well-known to developers, and the wider
set of computer-aware people.

If there were an ID change (which I don't want) I would argue for
ISO3166/BiggestCity, such as GB/London. Note that such an approach
allows for two IDs for the same city, useful in the middle east.


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