$termine = new WPAlchemy_MetaBox(array(
	'id' => '_termine',
	'title' => 'Termine',
	'types' => array('termine'),
	'template' => TEMPLATEPATH . '/MetaBoxen/termine.php',
	'save_filter' => 'antwortzeit_terminstempel'
));

function antwortzeit_terminstempel($meta, $post_id) {
    var_dump($meta);
    var_dump($post_id);
    exit;

    return $meta;
}

WPAlchemy save_filter

PHP