You can delete or archive employees that are no longer with you if you go to the 'Employees' tab.
When you archive an employee they will no longer be shown on time views and reports. However, in case you need it again you will be able to restore this user and all their data if you go to 'View Archive'.
When you delete an employee they will no longer be shown on the time views and reports. User will be permamently removed from your account, including their timesheet history and absence requests. This action cannot be undone.