title: pass parameter to date command through pipe
body: <p>to pass date and time to the <code>date -d</code> command by reading from file</p>
  
  <p>I tried: </p>
  
  <pre><code>#cat temp.txt
  2013/10/31 10:57:02
  #cat temp.txt | xargs date -d
  date: the argument `10:57:02' lacks a leading `+';
  when using an option to specify date(s), any non-option
  argument must be a format string beginning with `+'
  </code></pre>