Add 'New!' After Post title

Try it with this in your theme’s functions.php:

add_filter( 'widget_display_callback', 'categoryposts_custom_title', 10, 3 );

function categoryposts_custom_title( $instance, $widget, $args ) {

	if ( $widget->id_base == 'categoryposts' ) {
		add_filter( 'the_title', 'add_new_to_title', 10, 2 );
	}
	return $instance;
}

function add_new_to_title( $title, $id ) {

	$post = get_post( $id );

	if ( $post ) {
		if ( strtotime( $post->post_date ) > strtotime( '-30 days' ) ) {
			$title .= " New!";
		}
	}

	return $title;
}

btw:
consider creating a child theme instead of editing your theme directly – if you upgrade the theme all your modifications will be lost.

Hello,

thank you very much for the reply! It worked perfectly!

(P.s.: I already work with a childtheme, so that is no problem)