Datum en tijd invoegen in Mysql

$datetime = $_POST['date'] . ' ' . $_POST['time'] . ':00';
$datetime = mysql_real_escape_string($datetime);
$query = "INSERT INTO table(timestamp) VALUES ('$datetime')";

alternatieve oplossing die meer formaten aankan:

$datetime = $_POST['date'] . ' ' . $_POST['time'];
$datetime = mysql_real_escape_string($datetime);
$datetime = strtotime($datetime);
$datetime = date('Y-m-d H:i:s',$datetime);
$query = "INSERT INTO table(timestamp) VALUES ('$datetime')";