PHP: Wordpress last blog update jdate

gistfile1.php

<?php
function last_update() {
	global $wpdb;
	$date = $wpdb->get_var("SELECT DISTINCT post_date FROM $wpdb->posts WHERE post_date < '".current_time('mysql')."' AND post_status = 'publish' ORDER BY post_date DESC LIMIT 1");
	
	return jdate('l d M Y', strtotime($date));
}
?>