I'm concerned because it SEEMS to me that you haven't told us all of what you really want here.
When you open the table, Now() will be current date, surely enough, though you might have to format it as ScottGem suggests. But are you talking only about NEW records having Now() as their default or were you looking for more than that? After reading your question twice, I still have that nagging feeling that a vital factor in this problem description has been missed somehow.