How to Calculate the Time Difference Between Two Times in Excel 2003

1. Open Excel 2003, and select a workbook that contains columns with time information. Click 'File' on the menu bar, and select 'Open.' Browse your files, and select the workbook. Click the 'Open' button. The workbook opens.
2. Highlight the first column that contains time data. Right-click the highlighted data, and select 'Format Cells.' The Format Cells dialog box appears. Click the 'Number' tab. Select 'Time' from the 'Category' list. Select the first time format displayed. Click 'OK.'
3. Highlight the second column that will appear in the timed calculation. Press 'F4.' This repeats the previous timed number format.
4. In the third column, enter a time difference formula. The formula will subtract the first column from the second column. The formula will begin with an '=.' Click on the first cell in the first column and press the '-' key on your keyboard. Click the first cell in the second column and press 'Enter.'
5. Highlight the third column. Right-click the highlighted data, and select 'Format Cells.' The Format Cells dialog box appears. Click the 'Number' tab. Select 'Custom' from the 'Category' list. Select the time format that displays the following: '[h]:mm:ss.' Click 'OK.' Your difference column now displays the timed difference between the first and second column.