title: Regex to remove decimal values
body: <p>Given a timestamp in ISO 8601 format below:</p>
  
  <pre><code>2012-04-21T01:56:00.581550
  </code></pre>
  
  <p>what regular expression would remove the decimal point and the millisecond precision? In other words, a regex that applies to the above and returns the following:</p>
  
  <pre><code>2012-04-21T01:56:00
  </code></pre>
  
  <p>This is probably very simple, but not being particular familiar with regex I am unsure how to approach the solution. Thanks in advance for any assistance.</p>