How to use excel to find out overlapping time period?

Date Shift Start Time End Time
10/07/2013 Shift 09:00 17:00
10/07/2013 Shift 09:00 17:00
10/08/2013 Shift 09:00 17:00
10/09/2013 Shift 09:00 17:00
10/10/2013 Shift 09:00 17:00
10/11/2013 Shift 09:00 17:00
10/07/2013 Shift 09:00 17:00
10/07/2013 Twilight 09:00 17:00
10/08/2013 Shift 09:00 17:00
10/08/2013 Twilight 09:00 17:00
10/09/2013 Shift 09:00 17:00
10/09/2013 Twilight 09:00 17:00
10/10/2013 Shift 09:00 17:00
10/10/2013 Twilight 09:00 17:00
10/11/2013 Shift 09:00 17:00
10/11/2013 Twilight 09:00 17:00