A DESCRIPTION OF THE REQUEST :
The Australian time zone abbreviations given by Simple Date Format are different from the official time zone abbreviations as given in the Australian government website:
http://www.australia.gov.au/about-australia-13time

I ran this code:
import java.text.SimpleDateFormat;
public class AllTzIds {
    public static void main(String[] args) {
        SimpleDateFormat sdf = new SimpleDateFormat("dd-MMM-yy hh:mm a z");
        String[][] arr = sdf.getDateFormatSymbols().getZoneStrings();
        for (int i = 0; i < arr.length; i++) {
            String [] arr1 = arr[i];
            for(int j=0;j<arr1.length;j++){
                System.out.print(arr1[j]+" ");
            }
            System.out.println();
        }
    }
}

A part of the output (only showing timezones in Australia):

 Australia/ACT Eastern Standard Time (New South Wales) EST
 Australia/Adelaide Central Standard Time (South Australia) CST
 Australia/Brisbane Eastern Standard Time (Queensland) EST
 Australia/Broken_Hill Central Standard Time (South Australia/New South Wales) CST
 Australia/Canberra Eastern Standard Time (New South Wales) EST
 Australia/Darwin Central Standard Time (Northern Territory) CST
 Australia/Hobart Eastern Standard Time (Tasmania) EST
 Australia/LHI Load Howe Standard Time LHST
 Australia/Lindeman Eastern Standard Time (Queensland) EST
 Australia/Lord_Howe Load Howe Standard Time LHST
 Australia/Melbourne Eastern Standard Time (Victoria) EST
 Australia/North Central Standard Time (Northern Territory) CST
 Australia/NSW Eastern Standard Time (New South Wales) EST
 Australia/Perth Western Standard Time (Australia) WST
 Australia/Queensland Eastern Standard Time (Queensland) EST
 Australia/South Central Standard Time (South Australia) CST
 Australia/Sydney Eastern Standard Time (New South Wales) EST
 Australia/Tasmania Eastern Standard Time (Tasmania) EST
 Australia/Victoria Eastern Standard Time (Victoria) EST
 Australia/West Western Standard Time (Australia) WST
 Australia/Yancowinna Central Standard Time (South Australia/New South Wales) CST

These are not in synch with the time zone names ascribed to these regions in the Australian government website link given above.
Ex, South Australia's timezone should be returned as ACST, as apposed to CST that is returned by SimpleDateFormat.

JUSTIFICATION :
Making the time zone names unique across the world will make the time zone identification unambiguous.