title: Sort hashmap of arrays by datetime from array
body: <p>My hashmap is as follows:</p>
  
  <pre><code>variable_name[user] = { url, datetime }
  variable_name[user] &lt;&lt; { url1, datetime1 }
  variable_name[user] &lt;&lt; { url2, datetime2 }
  variable_name[user] &lt;&lt; { url3, datetime3 }
  </code></pre>
  
  <p>How can I sort this by datetime if possible in RoR?</p>
  
  <p>edit: variable_name is a hash, [user] is a key. the value is an array</p>