Extend Laravel’s validator class to fully validate dates in the format (DD/MM/YY). Tested in laravel 3.
public function validate_uk_date($attribute, $value, $parameters)
    {
        /*
        Validates a UK date to fit DD/MM/YY, checking for days in the month and accounting for leap years.
        Laravel's date validator didn't seem to do that.
         */
        //split date into array of parts
        $date_array = strptime ( $value, '%d/%m/%y' );
        //return early if that failed
        if ( ! $date_array ) return false;
        //check for validity of date
        return checkdate( (1+$date_array['tm_mon']), $date_array['tm_mday'], (1900+$date_array['tm_year']) );
    }