...
To change the date that displays on a resource, click into the “Publish Date” field. A calendar will open up and allow you to select a new date.
...
Publishing, Hiding, or Changing DatesDeleting
At the bottom of the page you will see options to 
a toggle that is most likely set to “publish.”
...
If you need to hide your article, simply toggle to the grey which is “unpublished.”
Please do not delete articles; we need to first know what other articles they link to and whether we should instead redirect the item.
...