<?php
    $myPost = new WP_Query( array(
    'posts_per_page' => '50',
    'orderby' => 'modified',
    'order' => 'DESC'
    ));
    while ($myPost->have_posts()): $myPost->the_post();
?>

<div class="timeline-group">
<p class="modified-time"><?php the_time('F j, Y') ?></p>
<h5><a href="<?php the_permalink();?>"><?php the_title();?></a></h5>
</div>

<?php
    endwhile;
    //Reset Post Data
    wp_reset_postdata();
?>