Procedure
If you are in the item display and want to switch to the totals display, choose Edit
® Total. Note where the cursor is, since the function is dependent on the cursor position:A window appears which contains different totals variants for selection. Choose Continue. The system displays the corresponding totals display.
The system totals the invoice items for the column on which the cursor is positioned.

The cursor is positioned on an invoice item in the column Difference days and you choose Edit