World Time Zone Map

Chuck Ellis chuck_ellis at
Sat May 10 02:24:35 UTC 1997

I am re-sending this message in the absence of any indication it was received 
the first time it was sent.  -Chuck Ellis


I have completed a Beta of a 1:1,000,000-scale world vector map of time zones 
and associated attribute data, including applicable Rule, ISO Country Codes, 
etc.  In reviewing the tz archive postings, it became clear that some of you 
are working towards the same end.  Therefore, I am posting the Beta to our 
company's FTP site in the hope that we can join forces to accelerate the 
development of this most useful map and data set.


I am a partner in MaconUSA, LLC, a digital mapping company based in Boston 
whose chief products are digital vector maps (with attached attribute data) of 

the world's political, administrative, civil, postal and telcomm boundaries.  
MaconUSA is the US "sister" company to Macon GmbH (Waghausel, Germany), which 
manufactures a suite of desktop mapping products for the European market. 
While we distribute primarily into the GIS market, our maps are for the most 
part focused on demographic, sales and marketing applications.  We have 
developed comprehensive boundary and features sets for Europe and the US, and 
are in the process of completing a Mexican/Caribbean/Central American/South 
American Map set.  We are Data Partners to virtually all of the major GIS 
application companies, such as ESRI, MapInfo, AutoDesk, Tactician, et al; our 
European maps are a (new) free inclusion in all of ESRI's shipping products.

We have fielded numerous requests over the past year from our customers for 
both an accurate/current worldwide time zone map, and an equivalent map 
delineating telephone country and area code boundaries; the time zone map is 
the completion of part one of this development effort.

While we are obviously a for-profit company, we are interested in a 
cooperative and public-interest effort regarding the time zone map.  I would 
envision such cooperation including joint posting/maintenance of a 
time zone-map web page freely accessible to the worldwide public, 
in ongoing standards-oriented work (such as it is or may become), etc.  The TZ 

archives maintained at appear to be as close to a defacto 
standards repository as a non-authoritative listserv can be; in the absence of 

any greater authority, we would prefer to work actively with it.

Time zone Map:

Three compressed files are posted at  --


The first file (time contains time zone.* (the primary time zone 
map and its attached attribute database); a rough readme.txt file for 
overview; tz_struc.txt which describes the attribute database in detail; 
city_550.* (the "top" 550 cities in the world as map points with tz 
atributes); mid_mif.txt (which is a detailed description of MapInfo's  ASCII 
vector map-file format that all boundary, point, and other map layers are 
written to, and is enough of a lingua franca to be transportable across many 
GIS and CAD applications).

The second file ( contains city_11k.* (a gazetteer of the "top" 
11,000 cities in the world as map points with tz atributes); airport.* (a 
second gazetteer of 14,000+ airports worldwide as map points with tz 
attributes); ports.* (a third gazetteer of 4,500+ Ports around the world 
plotted as map points with tz attributes); overlay.* (a simple grid of the old 

1884 GMT time zone lines for reference viewing; and ????struc.txt files 
detailing the file layouts for the gazetteer attribute databases.

The third file ( contains city_80k.* (a massive gazetteer of 
80,000 cities around the world plotted as map points with associated tz 

All three files are password protected. The password is:  proeger
The files have been zipped with pkzip v. 2.04g

Map Description:

The map is based upon Macon's own ISO-3166 standard world map, a commercial 
product that is updated semi-annually.  In turn, Macon's world map is based 
upon the original 1:1,000,000 DCW with a significant number of boundaries 
redrawn and/or updated to reflect current ISO-3166 definitions.  The Datum is 
WGS1984; this particular map is current to December 31, 1996.  The map was 
created in MapInfo, and has not yet been cleaned/processed with ArcInfo into a 

topological coverage (this will happen soon); the polygons are drawn in an 
essentially connect-the-dots sequence with preliminary shared-border snapping 
and de-duping.  Please refer to the mid_mif.txt file for a detailed 
description of MapInfo's ASCII vector format.  The 34 unique UTC-Offsets have 
been assigned colors according to a west-to-east spectral graduation using the 

Netscape 256-color chart (which is also Windows-compliant); these can be 
ignored or changed at will.

The gazetteer points are derived from different sources.  A significant number 

of just-onshore points appear slightly offshore due to being digitized from 
lower-scale maps and/or different datums; these have been properly attributed 
with tz data, but will be positionally adjusted in the final release.  
Nevertheless, the gazetteer collection has been included at this time because 
it is powerful testament to the primary advantage of defining detailed 
time zone polygons:  a simple point-in-polygon operation can in one pass 
tz attributes to a virtually limitless number of map objects.

Specific Time zone Notes:

We have had to take some liberties in this beta version:

1) Asia/Timor -- A specific objective in producing this file was maintenance 
of strict ISO-3166 compliance; in this case, the principal requirement was 
simply including every country in the ISO roster.  To wit, we added a new 
time zone, Asia/Timor, to represent East Timor.  It has been assigned the 
(default) rule, No_DST, which matches its neighboring zone, 
2) Atlantic/Madeira -- Even though Atlantic/Madeira is a duplicate of 
Europe/Lisbon, it was left as a distinct zone for cartographic purposes; 
linking far-flung polygons into one object can cause problems in many mapping 
applications when, for example,  centroids are calculated, labels are 
auto-placed, or MBR (minimum-bounding-rectangle) calculations are involved.
3) America/Dawson_Creek -- this boundary is approximate only, due to a lack of 

any refining information.
4) America/Regina, America/Winnipeg -- these boundaries obey all available 
notes from the archives, but are simply invented using provincial 
sub-boundaries and meridians/parallels in the absence of any meaningful 
feature definitions
5) America/Scoresbysund -- this boundary is approximate only, albeit probably 
very close
6) America/Thule -- same as (4) above
7) Asia/Aqtau, Asia/Aqtobe, Asia/Alma-Ata -- these boundaries were created 
using current provincial sub-boundaries in the absence of any refining data
8) Africa/Kinshasha, Africa/Lubumbashi -- same as (7) above
9) Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Magadan -- the 
boundaries between these zones are not well-defined; we used a CIA map from 
1994 at a scale of 1:5,000,000 to approximate these
10) America/Manaus, America/Fortaleza -- we defaulted the split between these 
two zones as a simple east-west meridian dividing Para
11) The attached tz attribute database defaults the ending year for 
currently-active Rules to 1999 for now to ease the burden on application 
developers using the data; this is obviously quite artificial, and any 
suggestions for how to handle this would be appreciated
12) The default Rule for countries with no active DST assignations is "No_DST"
13) Historical Zone and Rule information is for the most part not included; 
only in the case of a current Zone using a current Rule with a (provided) 
onset-date was the start-year included; we are happy to change this based on 
agreed-upon suggestions, but the drawing of historical zones is well beyond 
our scope.

Viewing the Time zone Map:

We apologize for not providing the tz map in a directly-viewable format just 
yet.  We are currently embedding the map with its associated database into an 
applet which I will upload in the coming weeks.  Those wishing to view the map 

at this time have the following alternatives:

a) Use MapInfo-- both the MapInfo Desktop and MapInfo Professional products 
can import mid-mif files directly, since it is the intermediate ASCII format 
for both applications
b) Use ArcView, BusinessMap, ArcInfo, or ArcCAD-- all ESRI products can import 

mid-mif files directly
c) Use Microsoft Excel Version 7 or higher, or Microsoft Office95 or higher-- 
these newer versions of Excel contain a feature called DataMap which can draw, 

color and query a MapInfo-BINARY format map directly; I will be posting the 
time zone map in this format in the next day or so as at
d) Use Any CAD Software-- I will be posting a .DXF version of the map in the 
next day or so as at
e) Write Your Own Viewer-- the mid-mif ASCII vector map format is quite 
simple, though with all of the applications out there capable of directly 
handling mid-mif, you're probably better off waiting for the Excel or CAD 
versions to post in the next day or so, or our own embedded viewer to post 
within the next couple of weeks.

Continued Development:

We are quite committed to upgrading, updating, and generally improving this 
map.  Any specific zone comments relating to how/where the boundaries are 
drawn are most useful if they provide or describe (in order of preference):  
the actual map, or a reference to where we can find it; underlying 
sub-boundaries (such as administrative or statistical or poitical or postal or 

municipal) comprising the zone; major land or water features which delineate a 

boundary or part of  boundary; a "legal" description (such as "follow rickety 
river six miles south, then east along provincial boundary..."); 
corrections/additions/deletions to the list of cities/towns included in a zone 

(you may find the gazetteer of 80,000 cities posted as noted above useful as a 

starter here).

Comments or Questions:

Please contact Chuck Ellis, at MaconUSA, 214 Lincoln Street, Suite 115, 
Allston, MA 02134, Tel 617-254-2295, Fax 617-254-2883, e-mail 
chuck_ellis at


Chuck Ellis

More information about the tz mailing list