Last modified

// Add Shortcode
function custom_shortcode() {

	$u_time = get_the_time('U'); 
	$u_modified_time = get_the_modified_time('U'); 
	if ($u_modified_time >= $u_time + 86400) { 
	echo "<p>Last modified on "; 
	the_modified_time('F jS, Y'); 
	echo " at "; 
	the_modified_time(); 
	echo "</p> "; 
	} 

}
add_shortcode( 'Last Modified', 'custom_shortcode' );