[tz] Dealing with Pre-1970 Data
David Patte ₯
dpatte at relativedata.com
Fri Aug 30 02:44:01 UTC 2013
Though it has been handy to have some pre-1970 data within the tz
database, I don't see that it is the best solution for historical tz
data in the long run. It is clear that that going back far enough in
time there is a different LMT for every 15 seconds of latitude.
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.
More information about the tz