Presently, the Event Calendar and the Event Calendar Highlights part display different date formats:

Event Calendar Format:                    WEEKDAY, MM DD, YYYY  HH:MM am/pm - HH:MM am/pm 
Event Calendar Highlights Format:   WEEKDAY, DD MM YYYY HH:MM am/pm - HH:MM am/pm

We are currently evaluating this issue and will update this article when we have more information.

There are no options to adjust the date format at this time.