I'm having problems finding how to set my Powerbook (OS X10.3) Timezone
to unusual areas. I wanted to use the System Preferences to set the
TimeZone to an unsupported geographical area I was travelling through.
The TimeZone is Central Western Australian time (covering small towns
like Eucla near the South Australian border), which is 45 minutes ahead
of Perth Time, and 45 minutes behind Adelaide. However this zone is
not one of the choices in the System Preferences.

In checking /usr/shar/zoneinfo/Australia I found there were entries for
other unusual areas (like Broken_Hill, which runs South Australian
time). I have (finally) learned that zic (zone information compiler)
can make an an entry for the Central West Australian zone. However,
this doesn't help, because I can't figure out how the System Preferences
decides which zones it shows (the zoneinfo folder contains many areas
and names that are not shown by System Preferences, including Broken
Hill and Lindeman Island).

Can anyone give me some hints on this matter?

In article
<NOSPAMjune2004-6DE23C.19215730082004@news-server.bigpond.net.au>,
Eric Lindsay <NOSPAMjune2004@ericlindsay.com> wrote:

>I'm having problems finding how to set my Powerbook (OS X10.3) Timezone
>to unusual areas. I wanted to use the System Preferences to set the
>TimeZone to an unsupported geographical area I was travelling through.
>The TimeZone is Central Western Australian time (covering small towns
>like Eucla near the South Australian border), which is 45 minutes ahead
>of Perth Time, and 45 minutes behind Adelaide. However this zone is
>not one of the choices in the System Preferences.
>
>In checking /usr/shar/zoneinfo/Australia I found there were entries for
>other unusual areas (like Broken_Hill, which runs South Australian
>time). I have (finally) learned that zic (zone information compiler)
>can make an an entry for the Central West Australian zone. However,
>this doesn't help, because I can't figure out how the System Preferences
>decides which zones it shows (the zoneinfo folder contains many areas
>and names that are not shown by System Preferences, including Broken
>Hill and Lindeman Island).
>
>Can anyone give me some hints on this matter?

Look in the Applications (Mac OS 9) : Apple Extras : Map Control Panel
folder. There is a readme and the actual Map Control Panel from OS 9. It
allows you to set things which are stored in the pram. However, OS X
tends to override it, so it may not be all that helpful.

--
Ron Parsons

In article <jrp59-F14070.08414930082004@news.verizon.net>,
Ron Parsons <jrp59@gte.net> wrote:

> Look in the Applications (Mac OS 9) : Apple Extras : Map Control Panel
> folder. There is a readme and the actual Map Control Panel from OS 9. It
> allows you to set things which are stored in the pram. However, OS X
> tends to override it, so it may not be all that helpful.

Not being used to the Mac, I didn't think of looking in the OS 9 stuff
(I don't believe I've ever used an OS 9 application), so thanks for that
tip. However, I'm not sure that what is needed is to actually alter the
time in the PRAM. I do recall MS-DOS used to set local times in the
BIOS, however I was pretty sure a current OS would be more likely to set
a PRAM time to Universal Time (rather than local time), and then apply
an offset according to which time zone you were in. You would surely
get some misleading file times unless something like this were done.

In article
<NOSPAMjune2004-126B75.17371531082004@news-server.bigpond.net.au>,
Eric Lindsay <NOSPAMjune2004@ericlindsay.com> wrote:

>In article <jrp59-F14070.08414930082004@news.verizon.net>,
> Ron Parsons <jrp59@gte.net> wrote:
>
>> Look in the Applications (Mac OS 9) : Apple Extras : Map Control Panel
>> folder. There is a readme and the actual Map Control Panel from OS 9. It
>> allows you to set things which are stored in the pram. However, OS X
>> tends to override it, so it may not be all that helpful.
>
>Not being used to the Mac, I didn't think of looking in the OS 9 stuff
>(I don't believe I've ever used an OS 9 application), so thanks for that
>tip. However, I'm not sure that what is needed is to actually alter the
>time in the PRAM. I do recall MS-DOS used to set local times in the
>BIOS, however I was pretty sure a current OS would be more likely to set
>a PRAM time to Universal Time (rather than local time), and then apply
>an offset according to which time zone you were in. You would surely
>get some misleading file times unless something like this were done.

You are correct. Macs have always kept time in UCT. They have also
always had a way to set the location and time offset in the PRAM. MacOS
X is somewhat disappointing in that it provides only a dumbed down
Choose One of These Cities approach. As far as I know, all the GPS
applications will set both current location and time but I don't know
how well MacOS X respects that. I do know that using the Map Control
Panel works to a degree, but even just checking it with MacOS X System
Preferences Date & Time will change your precise location to one of the
cities in your time zone, not necessarily the nearest one.

--
Ron Parsons