[tz] Comments and mapping of tz zones to the real world
tobias.conradi at gmail.com
Sun May 6 07:55:04 UTC 2012
On Sun, May 6, 2012 at 8:49 AM, Kevin Kenny <kkenny2 at nycap.rr.com> wrote:
> On 05/06/2012 02:03 AM, Tobias Conradi wrote:
>> Can you tell a way of how a user determines the correct zone for a
>> random location in Indiana, selecting between
>> America/New York
>> without reading the comments?
> Fortunately, nearly everyone in Indiana is aware of the bizarre
> timezone patchwork.
What do you mean by "bizarre timezone patchwork."? Do you mean the
existence of eleven zones for Indiana?
Adding to the above eight, these three:
I would assume many people wouldn't know that there are eleven tz
zones for locations in Indiana.
> The simple rule, "if you're in Eastern time with DST, use New_York,
> if you're in Eastern time without DST, use Indianapolis; if you're
> in Central time, use Chicago" is correct for 99% of them, because
> the breakaway counties are farmland with few inhabitants.
Using http://en.wikipedia.org/wiki/Time_in_Indiana#tz_database and
adding up Wikipedia 2010 population data for counties having a tz zone
that is not one of the three you singled out, namely Chicago,
New_York, Indianapolis, gives:
Indiana population is given with 6,483,802 for 2010. That is the three
zones you singled out contain 93.3% of the Indiana population at most,
thus cannot be correct for 99%.
> in the hinterland, it becomes "if you are in one of the half-dozen
> counties that have their own zones (named like the counties), use
I see no single zone that is named like a county.
The above county list contains two half dozens and one county. I don't
know what you mean by "the half-dozen counties that have their own
> If you were to pick a random location on a map in Indiana and ask
> what time is observed there, I'd be hard pressed to answer.
> in that particular case, better mapping might not even help;
I was asking for how to determine the tz zone without using the data
in the comments, i.e. without any mapping for individual counties at
all. Because on Sat, 5 May 2012 04:11:55 +0200 Robert Elz claims:
" erroneous comments are not a bug, as they don't affect the results"
> a great
> many inhabitants and businesses set their clocks to the large cities
> of Chicago or Indianapolis rather than whatever time their county
> legislatures have decided to observe that year.
Any example for this? It could be added to the tz database and improve
If only a minority in a given county does not observe what the law
mandates and is in the tz db comments, then having the comments
improves the results on average, thus the assumption "better mapping
[compared to no mapping] might not help" is wrong. If a majority in a
given country does not observe what the law mandates, I would ask on
the tz mailing list, whether the information for that area should be
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