I need to change Kentico date format to dd/MM/yyyy. I tried following the settings here https://docs.xperience.io/k12sp/configuring-kentico/reference-web-config-application-keys#ReferenceWeb.configapplicationkeys-Userinterfaceculturesettings
but looks like I'm gonna need a CMS.resx pack. Where do I get this language pack for Australia (en-AU)?
The language packs are available for download on the Devnet portal. However, in case of EN-AU, if you do not require translation of the resource strings to the Australian English (I guess the EN-AU is pretty much the same as EN-US in this case), you can simply copy the CMS.resx file and rename it CMS.en-au.resx. Or, you can use the CMSDefaultUICulture web.config key and set the default UI culture to EN-AU and then, the system will take the CMS.resx as the EN-AU culture's resource file. For more details please see the documentation on setting up multilingual UI.