1Click a cell where you want to locate the calculated result and then click Kutools Formula Helper Formula Helper see screenshot. The Date Time Wizard dialog window shows up you switch to the Difference tab and supply data for the formula. On the Ablebits Tools tab in the Date Time group click Date Time Wizard.
So you input the dates backwards.
DATE yyyy m d-DATE yyyy m d. The NETWORKDAYS Function is used to calculate working days in Excel between two dates. The number of weekends are automatically excluded. In this example the start date is in cell D9 and the end date is in E9.