John,
The date format will be following the portal language settings. For example, if your portal is set to use en-GB, it will be UK format, DNN default language is en-US.
Please check your portal settings, and also user settings because each user can have different locale.
On the other hand, if you want to format the date in the template, you also can do so, by using the token, for example: [EVENTDATE|dd/MM/yyyy] |