title: php convert local time to utc time taking into consideration Daylight savings
body: <p>suppose I have a certain date:</p>
  
  <pre><code>$date = mktime($hour, $minute, $second, $month, $day, $year);
  </code></pre>
  
  <p>this date is in local time, now how can I convert it to utc time and store the new hour, minute ... in php variables similar to $hour, $minute ...</p>