Getting records after a specific date.

Getting records after a specific date.

By now, I know how to set a criterion for a view to restrict by relative date, such as "within the last year" or "before today".

What I need is to know how to restrict a view to only show records after a specific date.

Background: I have an invoicing application, and for this one view, I only care about seeing unpaid invoices (Date_Paid is null) that were sent in or after 2010.  So I'm trying for something like Date_Sent > "2009-12-31" (which is the date format that my application uses), but I can't do it; I get an error that Date_Sent is a timestamp field.

I don't want a custom filter, unless I can somehow set that custom filter to be the default -- as in, to be the first thing I see when I go to the view.

Thanks.
-Christina