public static function FILETIMEtoUNIXtime($FILETIME, $round=true) {
    // FILETIME is a 64-bit unsigned integer representing
    // the number of 100-nanosecond intervals since January 1, 1601
    // UNIX timestamp is number of seconds since January 1, 1970
    // 116444736000000000 = 10000000 * 60 * 60 * 24 * 365 * 369 + 89 leap days
    if ($round) {
      return intval(round(($FILETIME - 116444736000000000) / 10000000));
    }
    return ($FILETIME - 116444736000000000) / 10000000;
  }