title: Join date and time strings into a DateTime
body: <p>Given two strings with the following values:</p>
  
  <pre class="lang-none prettyprint-override"><code>31/05/2013 0:00:00
  21:22
  </code></pre>
  
  <p>What's the most efficient way to join them into a <code>DateTime</code> data type to get:</p>
  
  <pre class="lang-none prettyprint-override"><code>31/05/2013 21:22
  </code></pre>
  
  <p>The time portion of the first string "0:00:00" is ignored, in favor of using the "time" from the second string.</p>