How do I add a timezone offset to this query?

Question

Problem is that $today is pulling GMT from the database; I need to offset GMT by -6 hours; Have been unable to find a query with an offset like that.

<?php
   $paged = ( get_query_var('paged') ) ? get_query_var('paged') : 1;
   $today = date('Y-m-d');
   query_posts(array(
   'post_type' => 'performance', 
   'posts_per_page' => 4, 
   'caller_get_posts' => 4, 
   'paged' => $paged,
   'meta_key' => 'order-date',
   'orderby' => 'meta_value',
   'order' => 'ASC',
       'meta_query' => array(
           array(
             'key' => 'order-date',
             'meta-value' => $value,
             'value' => $today,
             'compare' => '>=',
             'type' => 'CHAR'
         )
      )
    ));
  if (have_posts()) :
  while (have_posts()) : the_post();
?>