Reporting on timesheets

Does anyone know a way to report on when staff have submitted their timesheets? We're switching from another system to Workfront as the source of truth for hours logged to projects. I'd like a team leader (timesheet approver) to have a report which shows the date and time of every timesheet submission so they can chat with those who are habitually late. I can play around with last note (Notes worked quite well in auditing approval flows) but it seems to me if someone adds a comment, it becomes the 'last note' and the timestamp is wrong. Any thoughts?