Why is the End Time "01-jan-00 00:00:00" for the report object output I sent to the Completed Reports Folder?

When you select to have the output of a report object sent to the Completed Reports folder, it allows you to continue working within the IUIE while the output is being produced by the job running in the background.

If you go to the Job Log within My Catalog and view the detail of the job which is running in the background before the report object has completed running, you will find the End Time is set to "01-jan-00 00:00:00". When your report object completes, the correct End Time will be displayed when you view the Job Log again.