Date storage issue

I have insurance dates that are formated to appear by PHP to appear DD-MM-YYYY
this form info needs to be stored with an order (summary)

Opening the store Cart Summary SB (view columns against values)
and checking the DB Column InsuredPolicyExDate - I get type text
the DB field it refers to is type DATE

I set the field to date - but this is never saved and it reverts to TEXT?
and I just get a blank entry 0000-00-00 in my order

AS a last resort I set it to MSDATE (which stuck - but I get a MYSQL error on insert)

Is this the SB interface not working correctly

Note: There's obviously no way for the cart to know the format of the date is
Suggest this feature is added to the cart general settings - page 1


I need a way to get from the human readable
DD-MM-YYYY
php formatted display date

back into the correct format for the summary insert

if the text is entered
DD-MM-YYYY

then
// convert back the dates to mysql format

//list($d,$m,$y) = explode('-',$_SESSION['insure_date']);
//$_SESSION['insure_date'] = $y."-".$m."-".$d;

//list($d,$m,$y) = explode('-',$_SESSION['health_date']);
//$_SESSION['health_date'] = $y."-".$m."-".$d;

seems to do the trick if I echo it directly to the page to check it visually

but I still get 0000-00-00 in my database insert?

please advise