It is 2020 and Microsoft still believe everyone is in the USA (or covid central as it is now known). So we always have to change, normally an Administrator can do this, but in Server 2019, not even normal admin users can do this, you need to elevate the control.
You can change the time zone in the control panel, and it will fail with a notification that you do not have the permissions to perform this task and that you should contact the administrator.
If you try and change it in the 'settings app' you do not even get an error message; the dialog simply resets itself to the original time zone after exiting.
But they way to do it is starting the control panel's "timedate.cpl" applet directly, elevated with administrative rights.
You can also use the timezone utility, 'tzutil /s "AUS Eastern Standard Time"'
