There's been previous conversations about how "before" date filters include blank values, and whether or not that is ideal behavior. I think the best solution to this would actually be to add another constraint to date/datetime fields called "include blanks: true/false." That way you could make determinations definitively whether blank dates should be included in each filter.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.