Redmine

Does anyone know if there is a Redmine plugin that provides functionality for Weekly Timesheets to be used by employees or contractors? The timetracking features of Redmine are nice. But I am looking for something that my guys can use to report their entire time for the week (all 40 hours, for example). So it would be on a "user" basis, instead of a "task" basis. It will also allow users to account for overhead, administrative, or other non-billable time.

Thanks!

Jeff