As you need please use below method. it will give you proper month formated date
func monthFormatechange(_ dateString : String) -> String
{
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd-MM-yyyy"
let date = dateFormatter.date(from:dateString)
dateFormatter.dateFormat = "dd-MMM-yyyy"
let actualDate = dateFormatter.string(from: date!)
return actualDate
}
solved Date string convertion wrong month