For example: users should be able to enter date like this 31/02/2013 and when control lost the focus the date should convert to 28/02/2013

Resolution:
This behavior could be achieved with the new FreeFormDateTimeProvider. Whit this provider user is not restricted from any mask and could enter the date in desire format. This provider is integrated in RadMakedEditBox so it can be used in RadDateTimePicker and RadTimePicker. To change default provider of RadDateTimePicker you should change the mask type of embedded RadMaskEditBox into RadDateTimePicker. For Example:

 this.radDateTimePicker1.DateTimePickerElement.TextBoxElement.MaskType = MaskType.FreeFormDateTime;