There might be others - but the two ways I know of:

• Modify the configuration of the timer catch event to release the item sooner, then restart the Forms Routing Service (triggers timer to re-evaluate), then reverse your modification.  This has a risk of impacting other forms that get to the timer catch event during the time it is modified.
• Modify the value that was submitted on the form in the database.  To do this, look at the process (like from the Monitor page) and determine which submission_id in the process added that date field (if you have multiple tasks and activities, you may have to look through them all to determine at which point the value was populated).  Then check the cf_bp_data table in the database for items with that submission_id.  You might be able to tell which field is is simply by the value, but if not, you would need to check some other tables to determine wihch attribute_id belongs to which field.  Once you determine which item it is, edit that value to what you need it to be (be EXTREMELY careful here to ensure you're only editing that one value, write a careful SELECT statement that returns that one value before modifying it to be an UPDATE statement, and make sure you backups are recent).  Once you have edited that value restart the Forms Routing Service (triggers timer to re-evaluate).  This has the benefit of only impacting the one form and no others in progress, but big risks of screwing up your database if you are not careful - PROCEED AT YOUR OWN RISK.
  • I heard that version 11 will have some ability to edit field values after submission, so that would elminate needing to edit this directly in the database - so that's something to look forward to.