well, actually sort of solved my own problem, would still like to know why the above didnt work but used the following to get round it -
$datetime = $row["eventdate"];
$year = substr($datetime,0,4);
$mon = substr($datetime,5,2);
$day = substr($datetime,8,2);
$testdate = $day."-".$mon."-".$year;
echo $testdate;