title: convert character to 12H time format in R
body: <p>I need to convert a time in character "01:15:55 AM" to time.
  I was thinking of using chron library, however I am not sure how to do the format.</p>
  
  <pre><code>chron(times = "01:15:55 AM", format = "%I:%M:%S %p")
  Error in parse.format(format) : unrecognized format %I:%M:%S %p
  </code></pre>
  
  <p>Any ideas? I'm happy to try other libraries</p>