title: Why Wordpress using two column to store post date
body: <p>I see wordpress database on <code>wp_posts</code> table, there are 2 columns to store post date, <code>post_date</code> and <code>post_date_gmt</code></p>
  
  <p><code>post_date_gmt</code> store the post date in GMT time. And <code>post_date</code> store post date in user time who create the post. Am I right?</p>
  
  <p>Is there any benefit to store both version of post date on database?</p>
  
  <p>Is it faster to store both version of post date rather than calculate <code>post_date_gmt</code> with user timezone when user want to view post date based on his/her timezone</p>
  
  <p><strong>UPDATE</strong>:
  I Also ask on site point and get this answer</p>
  
  <blockquote>
    <p>The one benefit it would provide is
    that if the person moves to a
    different timezone then their earlier
    posts still record what time it was
    where they were when they posted them
    and not what time it was where they
    are now (as would be all you could
    calculate using the GMT time and their
    current timezone).</p>
  </blockquote>
  
  <p><a href="http://www.sitepoint.com/forums/showthread.php?p=4671837" rel="noreferrer">http://www.sitepoint.com/forums/showthread.php?p=4671837</a></p>