Fix incorrect tag

Author: pierredup

Diff for: _includes/themes/twitter/post.html

@@ -5,7 +5,7 @@ <h1>{{ page.title }} {% if page.tagline %}<small>{{page.tagline}}</small>{% endi
 <div class="row-fluid post-full">
   <div class="span12">
     <div class="date">
-      <span>{{ page.date | date_to_long_string }}</strong>
+      <span>{{ page.date | date_to_long_string }}</span>
     </div>
     <div class="content">
       {{ content }}
@@ -46,4 +46,4 @@ <h1>{{ page.title }} {% if page.tagline %}<small>{{page.tagline}}</small>{% endi
     <hr>
     {% include JB/comments %}
   </div>
-</div>
+</div>