Update

public/assets/js/mastodon.js

@@ -71,6 +71,15 @@ async function fetchData(log, tpl) {
                 post_tpl = post_tpl.replace(/{created_at}/g, `${value}`);
             }
 
+            if(key == "created_at") {
+                var isoDate = `${value}`;
+                var d = new Date(isoDate);
+                //var datetime_ =  d.toLocaleDateString('en-GB'); // dd/mm/yyyy
+                var datetime_ = d.toLocaleDateString('ru-RU');
+
+                post_tpl = post_tpl.replace(/{created_at_show}/g, `${datetime_}`);
+            }
+
             if(key == "edited_at") {
                 post_tpl = post_tpl.replace(/{edited_at}/g, `${value}`);
             }

public/json/mastodon-tpl.html

@@ -12,7 +12,7 @@
       <div class="col-md-6">
         <a href="https://{server_address}/@{name}/{post_id}" target="_blank" rel="noopener noreferrer">
           <span><i class="fa fa-globe" title="Публичный"></i></span>
-          <time datetime="{created_at}" title="{created_at}">{created_at}</time>
+          <time datetime="{created_at}" title="{created_at}">{created_at_show}</time>
           <abbr title="Последнее изменение: {edited_at}"> *</abbr>
         </a>
       </div>