Hi Douglas,
I dont think you will be able to make a report based on the shift. You need to contact your SAP team to built a report for your requirement.
In standard report, you cannot get output 17:00 to 06:00 next day, since the lower limit is greater than upper limit is not possible.
One alternate option, you need to have different variant for 19:00 to 23:59 and 00:00 to 07:00. You can use by choosing Completed Status and Completion date to capture the list of completion notification.
Then in the layout, you can set the filter with reference time. 3 layouts required for one day report.
Before coming to conclusion, you can contact your SAP team, may be they can create a variant or layout or new report for your purpose.
Regards
Terence