+``(and (date 2009-11-18 2009-11-18) (tag unread))``
+
+ Match messages in the given date range with tag unread.
+
+``(and (date 2009-11-18 *) (tag unread))``
+
+ Match messages from 2009-11-18 or later with tag unread.
+
+``(and (date * 2009-11-18) (tag unread))``
+
+ Match messages from 2009-11-18 or earlier with tag unread.
+