Show date but not time for each posts.

static/blog_index.tmpl.html

@@ -32,8 +32,8 @@
           <article class="post">
             <h2 class="post-title"><a href="{{ post.link }}">{{ post.title }}</a></h2>
             <div class="post-metadata">
-              <time datetime="{{ post.post_publication_date }}">
-                {{ post.post_publication_date }}
+              <time class="post-publication-date" datetime="{{ post.post_publication_date.date() }}">
+                {{ post.post_publication_date.date() }}
               </time>
               <ul class="post-tags">
                 {% for post_tag in post.post_tags %}