$today = date("Y-m-d H:i:s"); //Today's date

$daysago = date("Y-m-d H:i:s",strtotime(date('Y-m-j H:i:s')) - (1 * 24 * 60 * 60)); //Today - 1 day

$numposts = $wpdb->get_var("SELECT COUNT(*) FROM $wpdb->posts

WHERE post_status = 'publish' AND post_date BETWEEN '$daysago' AND

'$today'");

if ($numposts >0) {

echo $numposts.' posts published today';

} else {

echo "No posts published today";