Excel 2007

Edit: As shg correctly points out, every date in your existing spreadsheets will change.

Instructions:

  1. Click office button (Top left corner)
  2. Click Excel options
  3. Click "Advanced"
  4. Enable "Use 1904 date system"
  5. Click ok!

Type 08:00 in cell A1, type 09:00 in cell B1.