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.

Related posts:

Insert a new row at the top every time a value has been entered

Find positive and negative amounts that net to zero in excel

Count entries between date and time criteria in excel

Calculate your stock portfolio performance in excel

Why use R1C1?