displaying date in WPF

Question

• • hi,
    iam using devexpress date edit control.
    here i want the format "dd-MMM-YYYY(04-Nov-2014) to be displayed in date edit control.
    i achieved that with DisplayFormatString="dd-MMM-yyyy". but whenever iam selecting the date in dateedit control and it is again coming to dd-mm-yyyy (04-11-2014) format.
    whenever iam selecting the date, that time also i want to display in the format of dd-MMM-YYYY.
    even though when the cursor is there in date edit control the format should be dd-MMM-YYYY.
    here iam attaching the sample pictures.