When one of you employees forgot to clock in or out you can adjust the time entry time by clicking the 'edit icon' (pencil) of that wrong entry. If your employee completely forgot to register you can also add a time entry manually.
Choose in the menu for Schedule - Time Entry overview. Click on the red button on the right.
Under the clocked hours a field will appear.
Fill in the necessary data:
Select the employee
Choose the day
Fill in the hours
You can also add a reason.
If you filled in the data, click on 'Save working time'. If it succeeded, you'll see a pop-up.
The working time will appear in the overview and at the back of the row you'll see the checkmark 'Manual'.