title: Convert numbers to dates
body: <p>I have a table, one of the columns is dates in form at <code>20130109</code> or YearMonthDay with no spacing.</p>
  
  <p>I'm trying to graph these points, and because of this odd spacing, end up with big gaps in the graph, and thus want to convert these numbers into dates.</p>
  
  <p>I've been trying to use <code>as.Date(as.character(20130107), "%y%m%d")</code> but that always returns an <code>NA</code>.</p>