title: How to remove date from strptime and plot
body: <p>I have a variable, time, that is in Hour-Second-Minute format.</p>
  
  <pre><code>time &lt;- "01:01:52"
  </code></pre>
  
  <p>I want to have a new time-format variable, time2.</p>
  
  <p>I try:</p>
  
  <pre><code>strptime(db[1,10], format = "%H:%M:%S")
  </code></pre>
  
  <p>This returns</p>
  
  <pre><code>"2014-01-30 01:01:52"
  </code></pre>
  
  <p>How do I get rid of the Year-Month-Date portion of this?</p>
  
  <p>I have absolutely no attachment to the "POSIXlt" or "POSIXt" classes.  I am trying to plot a bunch of times on a histogram.  Can I use ggplot2 to do so?  If not, what is the best way to plot times?</p>