Make scheduled posts show as "Not Live Yet" rather than "Not Found"?

I like that idea. I coded it in a custom plugin, but I think the same code will probably work in a child theme’s functions.php file.

This hastily written and barely tested sample code checks that WordPress is about to display a single post in the category news and with a future date. In that case it changes the status to publish to make WordPress display the post, and it changes the title and content of the post. The changes are not stored in the database.

function ny_post_results ($posts) {
	if (count($posts) == 1
		&& in_category('news', $posts[0])
		&& $posts[0]->post_status == 'future') {
			$posts[0]->post_status = 'publish';
			$posts[0]->post_title = '<span style="color: gray;">Not yet published</span>';
			$posts[0]->post_content = 'The post you are looking for has not been published yet.';
			}
	return $posts;
	}
add_filter('posts_results', 'ny_post_results');