Hi,
Currently there is no configuration to allow you to change the date format, it uses long date format and the format is automatically localized according to the user's preferred language as specified in browser settings.
mojoPortal is not a "script", it is not written in a scripting language, it is pre-compiled into dlls from the C# source code.
Maybe sometime I will add some settings to allow tuning the date format, but you should not try to modify code in mojoPortal, if you do that you are forking the code and it will be difficult for you to upgrade without losing your changes.
Hope it helps,
Joe