title: PHP date_default_timezone_set() from GMT offset is possible?
body: <p>PHP date_default_timezone_set() from GMT offset is possible?</p>
  
  <p>im mySQL db I have:</p>
  
  <pre><code>|timezoneid  |  gmt_offset  |  dst_offset |  timezone_code | zone_name
  |    1       |    -12       |     0       |      NULL      |    (GMT-12:00) International Date Line West
  </code></pre>
  
  <p>I want to be able to set time zones from database</p>