Defaults the Time Zone for the database. This is a mandatory field, regardless of whether or not Time Zones are being used.
If multiple Time Zones are used, tick this option and then tick all the appropriate "Available" Time Zones, i.e. (UTC+09:30) Adelaide, (UTC+09:30) Darwin, (UTC+10:00) Brisbane and (UTC+10:00) Canberra, Melbourne, Sydney.
User Preferences allow each User to override the default Time Zone.
When entering Date and Times, e.g. the Log Date, you can enter the Date, Time and Time Zone.