Here are some rough notes and a script I thought I would quickly share with the community on this one. It is possible to adapt this for other regions.

The following script is based on Novel TID 3655154 and is customised for Australia.

It will do the following:
1) Create /tmp/timezone and /tmp/timzone/log
2) Generate some before log files
3) Download tzdata2008b.tar.gz from ftp://elsie.nci.nih.gov/pub/
4) Extract and update the australasia time zones
5) Generate some after log files

To use:

After you have downloaded the file at the bottom of the article, rename it with a .sh

mv ./Aus-Time-Zone-08.txt ./Aus-Time-Zone-08.sh

Edit the script and uncomment your time zone and save the file.

For Example uncomment:

zic -l Australia/NSW

Make sure it is executable:

chmod  x ./Aus-Time-Zone-08.sh

Run the script as root

./Aus-Time-Zone-08.sh

If you did not uncomment the command to relink your localtime setting with the corrected timezone then run:
zic -l localtimezone

For Example:

zic -l Australia/NSW

A few points to note:
Please review TID 3655154 for more information

Restart/Resync NTP

Assuming you are using and NTP time source, you may also want to restart/resync NTP when after the update:

OES1/SLES9
1) rcxntpd stop
2) ntpdate
3) rcxntpd start

OES2/SLES10
1) rcntpd stop
2) ntpdate
3) rcntpd start