PROBLEM No date/time information after update to 3.3.10

[Hypertexter]

PHP error log is empty.

I switched from my modified Innovation theme to the standard Cardinal theme, and Cardinal displays a "Published on  August 9th, 2016" at the bottom of the page.

What I had in Innovation template.php and what always worked online was

PHP Code:

<article>
            
            <section>
                
                <!-- title and content -->
                <h1><?php get_page_title(); ?></h1>
                <?php get_page_content(); ?>
                
                <!-- page footer -->
                <div class="footer">
                    <?php /* <p>Published on <time datetime="<?php get_page_date.strftime('Y-m-d'); ?>" pubdate> */ ?>
                    Heute ist <?php echo strftime("%A, der %-d. %B %Y"); ?>
                </div>
            </section>
            
        </article> 


OK, that was not the published date, but the actual date. But it worked.

But in both themes no date in News Manager posts...