title: Converting dates with a format of d/mm/yy (for years earlier than 69)
body: <p>Converting the character "6/07/69" into a date using the <code>as.Date</code> function results in "2068-07-06" instead of "1968-07-06". How can I fix this?</p>
  
  <p>Example:</p>
  
  <pre><code>as.Date(c("6/07/68", "6/07/69"), format="%d/%m/%y")
  [1] "2068-07-06" "1969-07-06"
  </code></pre>