fieldname: dob
type: date (y:m:d)

views code:

<?php echo $html->dayOptionTag('Client/d', $value = null, $selected =
null, $selectAttr = null, $optionAttr = null, $showEmpty = true);?>
                <?php echo $html->monthOptionTag('Client/m', $value = null,
$selected = null, $selectAttr = null, $optionAttr = null, $showEmpty =
true)?>

                <?php echo $html->yearOptionTag('Client/y', $value = null, $minYear
= null, $maxYear = null, $selected = null, $selectAttr = null,
$optionAttr = null, $showEmpty = true)?>

In the controller i have the code,

$this->Client->save($this->data);

1.  How do i save date, month, year in one field?

2.  The controller has many drop down (select tag), whose data is
coming from different tables.  While saving should i have to say as
$this-Client->save?  The class has been declared as,
 class ClientsController extends AppController

3.  As i have allready mentioned the controller code contains many
dropdown tag.
   example : $this->set('City', $this->City->generateList(
                null, "city_id ASC", null, "{n}.City.city_id",
                "{n}.City.city")
                );