Z600 message timestamp wrong

Posted by fusgerm
The timestamp of most of my arriving SMS messages is displayed as one hour in the future.

When I download the messages to a PC, I can see why: The handset is just displaying the local time of the sending SMSC, without changing it to the local time I have set in the handset. In other words, it is ignoring the timezone field of the message-header altogether.

I am in Queensland, Australia. Two of the four main carriers here use Sydney time, and their messages are all displayed post-dated by one hour. The other two carriers use Brisbane time, and their timestamps are displayed correctly.

None of this would matter if the Z600 adjusted the timestamp according to the local time configured in the phone (viz GMT+10 hr). How can I make it do that?