The client is asking for the date format DD-MMM-YYYY. Of course three separate fields is not a solution.
Looked at the previous thread below and I just can't believe that this can't be done. With other premium WordPress products that I pay for (themes, other plugins, etc), I see users get help with this minor degree of customization all the time.
I understand it will break if I update, that's not a problem.
Please either explain how to make this change (I am fine overwriting one of the existing date types if that makes it easier... the one with periods, for instance). Or at the very least, if I am forced to cobbled it together from three fields, please explain how to merge those into one field in the back end.