Using global $post; with custom post types

How about this? (Add to your theme’s functions.php file, or to a plugin.)

function new_post_alert() {
    global $post;
    $ageunix = get_the_time( 'U' );
    $days_old_in_seconds = time() - $ageunix;
    $days_old = $days_old_in_seconds / 86400;
    $post_type = get_post_type();

    if ( ( $days_old < 3 ) && ( 'news' === $post_type ) ) { ?>
        <script type="text/javascript">
            jQuery(document).ready(function($){
                $("#notification").addClass("notification-highlight");
                //alert('new!');
            });
        </script><?php
    }
}
add_action( 'wp_footer', 'new_post_alert' );