Choosing to restrict forum ratings by date causes an error as described in this discussion: http://moodle.org/mod/forum/discuss.php?d=175888. The problem is that the code in mod/forum/lib.php that does the date comparison tries to compare against a non-existent column. This defect was introduced with the fix for MDL-26838.
The line that reads
should be changed to
Searching on "timecreated" will take you directly to the line with the defect.