The date time format can be chosen in application settings

app/Template/app/notifications.php

@@ -49,7 +49,7 @@
                 <?php endif ?>
             </td>
             <td>
-                <?= dt('%B %e, %Y at %k:%M %p', $notification['date_creation']) ?>
+                <?= $this->dt->datetime($notification['date_creation']) ?>
             </td>
             <td>
                 <i class="fa fa-check fa-fw"></i>

app/Template/app/tasks.php

@@ -33,7 +33,7 @@
                 <?php endif ?>
             </td>
             <td>
-                <?= dt('%B %e, %Y', $task['date_due']) ?>
+                <?= $this->dt->date($task['date_due']) ?>
             </td>
         </tr>
         <?php endforeach ?>