Clear date filters on list views

As an Aha! user, I would like to be able to clear date filters from a list view so that I can see all items in the list without having to remove the filter field altogether.  Currently, there is no option to show items that don't have a date value.  Once you use the filter, you're forced into always applying it until you remove it because there are only radio buttons to choose from and at least one of them must be selected at all times.  Please add a "Clear all" option.