title: Timestamp format in application log
body: <p>I am writing the logs for my cloud hosted application in JSON format.  </p>
  
  <p>Ex:</p>
  
  <pre>
  {"timestamp":1343205650,"app_name":"gmail","app_version":"2.45467","category":"Info","err_no":-1,"message":"Started","source_file":"appstartcrawler.cc","source_line":79}
  </pre>
  
  <p>The log is later parsed and indexed by Splunk.</p>
  
  <p>My question is what format should I use for timestamp and why? Some of the options are:</p>
  
  <ol>
  <li>ISO 8601 (ex: 2004-02-12T15:19:21+00:00)</li>
  <li>RFC 2822 (ex: Thu, 21 Dec 2000 16:01:07 +0200) </li>
  <li>Unix timestamp</li>
  <li>MySQL format
  etc.</li>
  </ol>