Suppose you started to type Date, but then realized your mistake before pressing the Return key. The text you type is not sent to the system until you press Return. Therefore, it is still possible to correct your mistake. You have two choices:
Press the Delete or Backspace key to backspace to the error; or
Type Ctrl-U to erase the entire line and start over. (Hold down the Control key and press "u".)
Try both of these and see how they work. (The Delete/Backspace key varies on some systems. Ctrl-U should work on most systems.)