Here is how to reproduce:
1. Login to Sakai.
2. Without going to Assessment Settings page. Create an assessment and add some questions.
3. In Edit Assessment page, click on "Publish" link directly.
4. You will see an error asking you to select a retract date.
5. Select the date and click on "Save and Publish".
6. The error "Delivery Date is not of correct format: mm/dd/yyyy hh:mm:ss:aa." is seen.
Note: this error can only be seen if there is an error happens at step 4.