Hi there!

You can use the function in Excel to calculate the number of weeks between two dates. Here's how you can do it:

1. In the third column (duration), select the cell where you want to display the number of weeks.
2. Type the following formula:
   Code:

   =DATEDIF(A2,B2,"w")

   - A2 is the cell containing the start date
   - B2 is the cell containing the end date
   - "w" tells Excel to calculate the number of weeks between the two dates
3. Press Enter to calculate the number of weeks.

That's it! The duration column will now display the number of weeks between the start and end dates. Keep in mind that the function only works with dates in the same year, so if your start and end dates are in different years, you'll need to use a different formula. Let me know if you have any other questions!