title: Why does strtotime give different result in different timezone?
body: <p>I am not sure why <code>strtotime()</code> in PHP returns different result in different timezone even though same date is given as parameter, does anyone know the answer? I also want to know, can I do similar task (converting a <code>datetime</code> to an <code>int</code> to do calculations easily) with another function which gives same result across different timezone?</p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>An example:
  If I use <code>strtotime('2011-09-19 00:00:00')</code> shouldn't it just return the difference between <code>'January 1 1970 00:00:00'</code> and <code>'2011-09-19 00:00:00'</code> in seconds ? Why timezone is an issue here? And can I get something which gives just difference without timezone issue?</p>