Two reports show time written down based on when it was worked instead of billed – Summary of Hours Worked and Timekeeper Productivity; however, these reports do not tell you WHEN the time was written down on the reports.  If you use the Time Manager, you can set a filter to display time worked during a certain date range. You can then choose to display the fields Write Up/Down Amount and Invoice Date in your grid (right-click and choose Select Grid Fields). Once you have your data sorted, sort or filter by the Write Up/Down field.  You can then review the Invoice Date to get an idea of when the time was invoiced.