Date will be handled as part of upgrade Date cardtype.

Vague memory that we thought a workaround was to change cardtypes and blank out the card's content, but this doesn't work. See http://test.dwagn.org/wagn/test+blank_date_not_working and http://test.dwagn.org/wagn/blank_date_not_working+*rform

  --John Abbe.....Sat Aug 22 15:23:47 -0700 2009

I think as of wagn 1.8 this will be in a good state. I don't think a "revert to blank" button makes any sense -- interface noise. But the date editor is now more flexible (it's the default jquery ui date editor) and you can work around files and images by changing type away and back or by deleting and recreating.

  --Ethan McCutchen.....Thu Dec 01 15:16:01 -0800 2011