How to subtract date values in a calculated column
The following section describes how to display the difference between two date values.
1 Select a column. The calculated column appears to the right of the selected column. Choose New Computed Column. Calculation appears.
2 In Column Label, type a name for the calculated column. For example, for a calculation that subtracts the actual shipping date from the date requested, type Shipping Delay.
3 In Enter Expression, type the letter d. A drop-down list appears, displaying functions that begin with d.
5 For the first argument, type a left bracket ([) and select the first date column from the drop-down list. For example, select Date Requested.
6 For the second argument, type a left bracket ([) and select the second date column from the drop-down list. For example, select Actual Shipping Date.
7 Validate the expression and choose OK. The calculated column appears in the report, displaying the difference between the two dates.