Here is a short function to get the difference between two timezones in PHP:-

function diff(){
    $date1 = "2014-02-27T20:00:00+04:00"; 

    $date2 = "2014-02-28T07:20:00+08:00"; 

    $diff = abs(strtotime($date2) - strtotime($date1)); 
    $years   = floor($diff / (365*60*60*24)); 
    $months  = floor(($diff - $years * 365*60*60*24) / (30*60*60*24)); 
    $days    = floor(($diff - $years * 365*60*60*24 - $months*30*60*60*24)/ (60*60*24));
    $hours   = floor(($diff - $years * 365*60*60*24 - $months*30*60*60*24 - $days*60*60*24)/ (60*60)); 
    $minuts  = floor(($diff - $years * 365*60*60*24 - $months*30*60*60*24 - $days*60*60*24 - $hours*60*60)/ 60); 
    $seconds = floor(($diff - $years * 365*60*60*24 - $months*30*60*60*24 - $days*60*60*24 - $hours*60*60 - $minuts*60)); 
    printf("%d years, %d months, %d days, %d hours, %d minuts\n, %d seconds\n", $years, $months, $days, $hours, $minuts, $seconds); 


}
diff();