I used the date( ) function and this solved me the problem.
$stmt = $mysqli->prepare("INSERT INTO FOO (dateColumn) VALUES ?");
// 6/10/2015 10:30:00
$datetime = date("Y-m-d H:i:s", mktime(10, 30, 0, 6, 10, 2015));
$stmt->bind_param("s", $datetime);
$stmt->execute();