Unfortunately, SharePoint Designer doesn't do formatting OOTB.
So, the best way to solve your issue is to add a calculated field to your list and hide it from your users.
- If your list isn't set up to manage content types, you will want to change that, at least momentarily.
- Click on Settings -> List Settings
- Click on Advanced Settings
- Next to Content Types, set Allow management of content types? to Yes
- Click OK
- In List Settings, click on Create column
- Name the field (i.e. strDueDate)
- Choose Calculated (calculation based on other columns)
- Enter the following formula into Formula:
=TEXT([Due Date],"mm/dd/yyyy")
(or whatever format you want to display)
- Set the data type to Single line of text
- Leave Add to all content types checked
- Uncheck Add to default view
- Click OK
- Back on the List Settings page, under Content Types, click on the link for your content type (e.g. Item)
- Click on the name of your new column (e.g. strDueDate)
- Under Column Settings, set This column is: to Hidden (Will not appear in forms)
- Click OK
- If you were already managing content types, skip the next set of sub-steps
- Go back to the List Settings page and click on Advanced settings
- Change Allow management of content types? back to No
- Click OK
Now from SPD you can use your strDueDate field to display the date without the time.
