Quetico (and other places in NW Ontario)
Jesper Norgaard Welen
jnorgard at prodigy.net.mx
Sun Nov 5 20:20:18 UTC 2006
The map you sent of the Quetico park overview is more than sufficient for me
to make a reasonable timezone. After all this is not rocket science, I'm
intending to give an overview of the timezone for visual use, not for
calculating if a specific latitude/longitude is inside the timezone or not.
I'm using an ESRI shapefile map, you can check it out from downloading World
Time Explorer beta version from
http://www.worldtimeexplorer.com/wt20beta.zip and unzip and install it. I
can give you a free full license if you want, so you can generate map colors
for a specific date between 1850 and today. Otherwise the shareware version
will give you 30 days of playing around, and the colors should correspond
until 2007, except for a possible (undecided) change in West Australia of
course! And PS, I presume you have (access to) a Windows PC, otherwise it
will not be of much use! Linux die-hards, sorry!
I was wondering if my border between Rainy_River (on GMT-6) area and the
rest of Ontario (on GMT-5) is wrong, supposedly it should divide around 90°
while in reality it divides around -89.34. This is from another map source
where I copied this border from, but perhaps for timezone use I should move
It would be nice if you could plot the points from Quetico park (100 points
would be fine, perhaps even too much). I don't know if you have a
possibility to output to an ESRI shapefile. If not, a collection of the pure
latitude/longitudes would be fine (decimal please, not radix 60).
I will consider your comments about America/Winnipeg being one hour off each
year, but it seems that even tz database is correct in this case? It looks
# From Paul Eggert (2006-04-10):
# Shanks & Pottenger say Manitoba switched at 02:00 (not 02:00s)
# starting 1966. Since 02:00s is clearly correct for 1967 on, assume
# it was also 02:00s in 1966.
Rule Winn 1963 only - Sep 22 2:00 0 S
Rule Winn 1966 1986 - Apr lastSun 2:00s 1:00 D
Rule Winn 1966 2005 - Oct lastSun 2:00s 0 S
Rule Winn 1987 2005 - Apr Sun>=1 2:00s 1:00 D
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone America/Winnipeg -6:28:36 - LMT 1887 Jul 16
-6:00 Winn C%sT 2006
-6:00 Canada C%sT
Since 2:00s standard time means 3:00 local time when leaving DST, we're OK?
What would be the difference between the Kenora timezone and the others?
From: Chris Walton [mailto:Chris.Walton at telus.com]
Sent: Domingo, 05 de Noviembre de 2006 1:24
To: jnorgard at prodigy.net.mx; tz at elsie.nci.nih.gov; Paul Eggert
Subject: Quetico (and other places in NW Ontario)
It looks like the entire MNR site is down. It was working on Saturday
morning (Toronto time). Hopefully it will come up soon! The maps on this
site are actually scanned copies of paper maps; the idea being that you can
view an image of the map before you fork out money for a paper copy. The
resolution of the scanned images is terrible so the writing on the maps is
virtually impossible to read.
If you want a rough idea of the shape of the park have a peek at
Let me know if you want me to generate a set of points or if you would
prefer to do it yourself; I don't mind either way. I figure that the area
could be roughly defined with about 100 points but to properly follow the
park boundary would take around 2000 points.
And now putting Quetico aside for a minute... you need to decide which zone
to use for the "other" areas in Ontario west of 90°.
According the TZ database, Fort Frances and Rainy River did not use daylight
saving until 1974; this is why there is a dedicated zone called
America/Rainy_River. So Rainy River and Fort Frances should use
America/Rainy_River without question.
Presumably the rest of the region west of 90° has used CST/CDT since WWII.
According to the "zonetab" file, the region is supposed to use
America/Winnipeg results in incorrect times for one hour each year from 1966
through to 2005. This is because Manitoba "used" to change the clocks at
3:00a.m. every fall. The practice stopped this year. Ontario has always
changed the clocks 2:00a.m.
America/Rainy_River gives correct times for the entire region from 1974
Personally I think that America/Rainy_River is the better choice for the
entire region because it provides correct rules for the last 32 years.
Technically there should be another zone called America/Kenora but I doubt
anybody wants to bother creating it.
If it were up to me I would merge zones that have been the same for at least
25 years and create entries in the "backward" file for compatibility; but I
know this would be against the official rules!
More information about the tz