A Timesheet Invoice is a subtype of an Invoice. The main purpose of a Timesheet Invoice is to keep track of non invoiced hours logged.
Timesheet Invoices are created by the Timesheet Invoices Package. This package contains a Wizard that allows an Accountant to invoice the hours logged on a Time & Material project (a project where the customer pays the hours that the provider has spent on the project).The logged timesheet hours included in a Timesheet Invoice are marked as belonging to the Timesheet Invoice by setting im_hours.invoice_id to the ID of the Timesheet Invoice.
The main technical purpose of a Timesheet Invoices is to mark the invoiced timesheet hours as free if the Timesheet Invoice should be deleted.
ToDo: Insert screenshot from Timesheet Wizard.
ToDo: Insert database diagram showing how im_hours.invoice_id references im_timesheet_invoices.