Why don't news items respect the effective and expiration date?
The news portlet and News smart folder don't seem to use the effective date and expiration dates of a news item as criteria. You see news items that should become visible in the future, or expired in the past.
The effective and expiration date are handled by the portal catalog, not by the news smart folder or news portlet. That's why you don't see criteria for these fields in the smart folder and in the portlet's template.
The reason you see items from the future or the past is most likely that you're logged in as manager. Login as a regular user, or view your site anonymously (not logged in), refresh your page and you should see only news items with: effective date