The problem:
When you have multiple posts published on the same day, the post date only shows up for the first one when you view the posts on your site.

The fix:

  1. Go to “Appearance > Editor” and repeat the following steps for each of your theme files
  2. Look for instances of this code:
    <?php the_date(); ?>
  3. Replace that code with this code:
    <?php echo get_the_date(); ?>
  4. Click “Update File”

The explanation:
Most WordPress template tag functions that start with “the_” will merely output the values returned by their equivalent “get_the_” functions. However, “the_date()” is an exception to this standard because it adds functionality that’s not present in “get_the_date()”, namely, not outputting the same date more than once per page, which can be a feature or an annoyance depending on your desired functionality.