Amazon sets the default transit time for new shipping templates. The default transit time is the setting that is automatically populated when you create a new template. You are able to edit your shipping settings to ensure transit times match your delivery capabilities.
For Australia in particular, setting up different transit times per destination region is critical to provide customers with short and accurate delivery times. For instance, a customer living in Sydney will be able to receive a parcel significantly earlier than a customer living in a remote area of Western Australia. Your shipping settings need to account for different transit times between regions.
Click Step by Step Guide to learn more on how to set accurate transit times.