Discrepancy between zone.tab ordering and northamerica details

Olson, Arthur David (NIH/NCI) [E] olsona at dc37a.nci.nih.gov
Tue Oct 21 16:08:43 UTC 2008

Eric's change to zone.tab looks reasonable; unless someone finds a
problem I'll make it a part of next week's ftp version.


-----Original Message-----
From: Eric Fischer [mailto:enf at pobox.com] 
Sent: Monday, October 20, 2008 9:18
To: tz at lecserver.nci.nih.gov
Subject: Discrepancy between zone.tab ordering and northamerica details

We just ran into a bug at work where users in US Central Time were
identified as being in America/Indiana/Knox instead of in
America/Chicago because code was running through the list of time zones
in zone.tab looking for the first one that matched the current GMT
offset and DST state, and America/Indiana/Knox is currently observing
CDT and ordered before America/Chicago.

I hope this is actually a use that the file ordering is intended to
support, but even if it isn't, the zone.tab file seems to be misleading
for some Indiana towns.  In particular, northamerica says that
Petersburg is Eastern and Knox is Central, but zone.tab says that
Petersburg is Central and Knox is Eastern.  I've attached a patch to
bring zone.tab into line with northamerica, at least for these two


--- zone.tab.orig	2008-10-08 05:35:57.000000000 -0700
+++ zone.tab	2008-10-20 18:14:59.878269000 -0700
@@ -384,13 +384,13 @@
 US	+364947-0845057	America/Kentucky/Monticello	Eastern Time -
Kentucky - Wayne County
 US	+394606-0860929	America/Indiana/Indianapolis	Eastern Time -
Indiana - most locations
 US	+384038-0873143	America/Indiana/Vincennes	Eastern Time -
Indiana - Daviess, Dubois, Knox & Martin Counties
-US	+411745-0863730	America/Indiana/Knox	Eastern Time - Indiana -
Starke County
 US	+410305-0863611	America/Indiana/Winamac	Eastern Time - Indiana -
Pulaski County
 US	+382232-0862041	America/Indiana/Marengo	Eastern Time - Indiana -
Crawford County
+US	+382931-0871643	America/Indiana/Petersburg	Eastern Time -
Indiana - Pike County
 US	+384452-0850402	America/Indiana/Vevay	Eastern Time - Indiana -
Switzerland County
 US	+415100-0873900	America/Chicago	Central Time
 US	+375711-0864541	America/Indiana/Tell_City	Central Time -
Indiana - Perry County
-US	+382931-0871643	America/Indiana/Petersburg	Central Time -
Indiana - Pike County
+US	+411745-0863730	America/Indiana/Knox	Central Time - Indiana -
Starke County
 US	+450628-0873651	America/Menominee	Central Time - Michigan
- Dickinson, Gogebic, Iron & Menominee Counties
 US	+470659-1011757	America/North_Dakota/Center	Central Time -
North Dakota - Oliver County
 US	+465042-1012439	America/North_Dakota/New_Salem	Central Time -
North Dakota - Morton County (except Mandan area)

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