How do I edit the date/time stamp on submissions?

We are receiving mail-in registrations in addition to electronic registrations.  I need to be able to back date the mail-in submissions so they move to their proper place in line.  Is it possible?

Unfortunately, it is not possible to edit the date/time of when submissions were received.  You could add a date field to the form and edit that field for each submission.  You could then sort based on that date.  But the date that is assigned to the form by default when it is submitted can not be edited.