A DESCRIPTION OF THE REQUEST :
I need to ensure that the JVM has a particular Locale and TimeZone for a stock trading application.

I know how to do this programmatically, for instance:
Locale.setDefault( Locale.US );
TimeZone.setDefault( TimeZone.getTimeZone("America/New_York") );

But that is problematic: it requires me to insert code like that everywhere inside, say, the start of all my main methods. Just as bad: hardcoding something like that is obviously horrendous practice.

I would be very happy for an approach that specifies that info as command line arguments of the java command.

Articles like this
http://forum.java.sun.com/thread.jspa?threadID=551541&messageID=2696001
http://www.javaworld.com/javaworld/jw-10-2003/jw-1003-time.html?page=4
lead me to think that these command line arguments
-Duser.country=US
-Duser.timezone=America/New_York
should do the trick.

But System.getProperties, unfortunately, does not guarantee that user.country/user.timezone will be present, nor does Locale/TimeZone guarantee that it will honor it.

This is not a theoretical concern: that first forum posting claims that old JDKs used to "use -Duser.region, rather than -Duser.country". And this guy
http://brondsema.net/blog/index.php/2006/02/
(see the "Feb 07, 2006 : Timezones in Tomcat" entry)
reports that
-Duser.timezone=?? and env var TZ=?? may or may not work

What I need is for Sun to commit to standard properties here. The javadocs for System.getProperties (as well as, presumably, Locale and TimeZone) will need to be updated.


JUSTIFICATION :
My stock trading program uses dates (e.g. the time of market opens) that are obviously governed by the exchange's timezone.

My program, however, needs to work regardless of what timezone the machine running the code is in.

It turns out that it is easiest to write my code to always internally use the exchange's time zone.