title: How to convert a GMT timestamp to Unix timestamp (javascript)
body: <p>I'm parsing an rss feed and each entry has a timestamp such as this: 2009-09-21T21:24:43+04:00
  Is there any way to convert this date format to a unix timestamp with javascript?</p>
  
  <p>I just want to be able to record the latest rss entry date, but I need to standardize the time to GMT time or Unix timestamp to do this.</p>