title: Convert numeric to date
body: <p>I'd like to convert this type of numeric values to a date but it doesn't work.</p>
  
  <p><code>20100727</code> for instance</p>
  
  <p>I tried to convert the numeric to character and applied this :</p>
  
  <pre><code>as.Date("20100727", "Y%d%m")
  </code></pre>
  
  <p>but it doesn't work.</p>
  
  <p>How can I do ?</p>