title: MongoDB select data which is not older than a week
body: <p>So I'm trying to select data that is not older then I week, I need something like this from mysql:</p>
  
  <p><code>WHERE date &lt;= one week ago</code></p>
  
  <p>Here is my current query:</p>
  
  <pre><code>$this-&gt;aggregate(
                  array(
                      array('$sort' =&gt; array( '_id' =&gt; self::SORT_DESC)),
                      array('$match' =&gt; array( 'seen' =&gt; 0)),
                      array('$group' =&gt; array('_id'=&gt;'$target_user',
                          'type' =&gt; array('$push'=&gt; array('type' =&gt; '$type',
                              'title'=&gt;'$title',
                              'link'=&gt;'$link',
                              'dt'=&gt;'$dt',
                              'own'=&gt;'$own',
                              'usr'=&gt;'$usr'))
                          )),
                      ));
  </code></pre>
  
  <p>The field <code>dt</code> in <code>$group</code> is a string date which is stored like this: <code>2013-10-14 14:53:11</code> so based on the <code>dt</code> key I need data the isn't older than a week.</p>
  
  <p>Can something like this be done in Mongo?</p>