The initial step to adding an exception to a timesheet is to navigate to the timesheet in question. Once there, you can add a manual exception in two different ways.

1.  You can enter an exception directly from the timesheet on the Time Entry tab by clicking the ellipses next to the date and selecting Manage Exceptions.

Inside of the Manage Exceptions screen, you can click the +ADD button in the bottom of the screen and add an exception under the Exception Type field.

2.  The second way is to navigate to the Exceptions tab on the timesheet. This is the third tab of the timesheet. You can use the drop down to select the appropriate exception in this view.