/**
  * iCal spec represents date in ISO 8601 format followed by "T" then the time
  * a "Z at the end means the time is UTC and not local time zone
  *
  * TODO make sure if time is UTC we take account of system time offset properly
  *
  */
 function unixTime($ical_date, $tz = false)
 {
     jimport("joomla.utilities.date");
     static $offset = null;
     if (is_null($offset)) {
         $config =& JFactory::getConfig();
         $offset = $config->getValue('config.offset', 0);
     }
     if (!is_numeric($ical_date)) {
         $t = JevDate::strtotime($ical_date);
         if (JString::strpos($ical_date, "Z") > 0) {
             if (is_callable("date_default_timezone_set")) {
                 $timezone = date_default_timezone_get();
                 // See http://www.php.net/manual/en/timezones.php
                 $params = JComponentHelper::getParams(JEV_COM_COMPONENT);
                 // server offset tiemzone
                 if ($params->get("icaltimezone", "") != "") {
                     date_default_timezone_set($params->get("icaltimezone", ""));
                 }
                 // server offset PARAMS
                 $serveroffset1 = (JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%S', $t)) - JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%SZ', $t))) / 3600;
                 // server offset SERVER
                 date_default_timezone_set($timezone);
                 $serveroffset2 = (JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%S', $t)) - JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%SZ', $t))) / 3600;
                 $t = new JevDate($ical_date, $serveroffset1 - $serveroffset2);
                 //$t = new JevDate($ical_date );
                 date_default_timezone_set($timezone);
                 echo "icaldate = " . $ical_date . " imported date=" . $t->toMySQL() . "<br/>";
             } else {
                 // Summer Time adjustment
                 list($y, $m, $d, $h, $min, $s) = explode(":", JevDate::strftime('%Y:%m:%d:%H:%M:%S', $t));
                 $dst = (JevDate::mktime($h, $min, $s, $m, $d, $y, 0) - JevDate::mktime($h, $min, $s, $m, $d, $y, -1)) / 3600;
                 // server offset including DST
                 $serveroffset = (JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%S', $t)) - JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%SZ', $t))) / 3600;
                 $serveroffset += $dst;
                 $t = new JevDate($ical_date, -($serveroffset + $offset));
             }
             /*
             echo "<h3>SET TIMEZONE</h3>";
             $timezone= date_default_timezone_get();
             date_default_timezone_set('America/New_York');
             
             $tempIcal  = "20091020T163000Z";
             echo $tempIcal."<br/>";
             $temp = JevDate::strtotime($tempIcal);
             list($y,$m,$d,$h,$min,$s) = explode(":", JevDate::strftime('%Y:%m:%d:%H:%M:%S',$temp));
             echo "$y,$m,$d,$h,$min,$s<br/>";
             $dst = (JevDate::mktime($h,$min,$s,$m,$d,$y,0)-JevDate::mktime($h,$min,$s,$m,$d,$y,-1))/3600;
             $so = (JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%S',$temp))-JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%SZ',$temp)))/3600;
             echo " dst=".$dst." serverforoffset=".$so."<br/>";
             $so += $dst;
             $t = new JevDate($tempIcal);
             echo $t->toMySQL()."<br><br/>";
             
             
             $tempIcal  = "20091029T163000Z";
             echo $tempIcal."<br/>";
             $temp = JevDate::strtotime($tempIcal);
             list($y,$m,$d,$h,$min,$s) = explode(":", JevDate::strftime('%Y:%m:%d:%H:%M:%S',$temp));
             echo "$y,$m,$d,$h,$min,$s<br/>";
             $dst = (JevDate::mktime($h,$min,$s,$m,$d,$y,0)-JevDate::mktime($h,$min,$s,$m,$d,$y,-1))/3600;
             $so = (JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%S',$temp))-JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%SZ',$temp)))/3600;
             echo " dst=".$dst." serverforoffset=".$so."<br/>";
             $so += $dst;
             $t = new JevDate($tempIcal );
             echo $t->toMySQL()."<br><br/>";
             
             $tempIcal  = "20091103T163000Z";
             echo $tempIcal."<br/>";
             $temp = JevDate::strtotime($tempIcal);
             list($y,$m,$d,$h,$min,$s) = explode(":", JevDate::strftime('%Y:%m:%d:%H:%M:%S',$temp));
             echo "$y,$m,$d,$h,$min,$s<br/>";
             $dst = (JevDate::mktime($h,$min,$s,$m,$d,$y,0)-JevDate::mktime($h,$min,$s,$m,$d,$y,-1))/3600;
             $so = (JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%S',$temp))-JevDate::strtotime(JevDate::strftime('%Y%m%dT%H%M%SZ',$temp)))/3600;
             echo " dst=".$dst." serverforoffset=".$so."<br/>";
             $so += $dst;
             $t = new JevDate($tempIcal);
             echo $t->toMySQL()."<br>";
             */
         } else {
             if ($tz != false && $tz != "") {
                 // really should use the timezone of the inputted date
                 $tz = new DateTimeZone($tz);
                 $t = new JevDate($ical_date, $tz);
                 echo "icaldate = " . $ical_date . " imported date=" . $t->toMySQL() . "<br/>";
             } else {
                 $compparams = JComponentHelper::getParams(JEV_COM_COMPONENT);
                 $jtz = $compparams->get("icaltimezonelive", "");
                 if ($jtz) {
                     $t = new JevDate($ical_date, $jtz);
                 } else {
                     $t = new JevDate($ical_date);
                 }
             }
         }
         //$result = $t->toMySQL();
         $result = $t->toUnix();
         return $result;
     }
     $isUTC = false;
     if (JString::strpos($ical_date, "Z") !== false) {
         $isUTC = true;
     }
     // strip "T" and "Z" from the string
     $ical_date = str_replace('T', '', $ical_date);
     $ical_date = str_replace('Z', '', $ical_date);
     // split it out intyo YYYY MM DD HH MM SS
     preg_match("#([0-9]{4})([0-9]{2})([0-9]{2})([0-9]{0,2})([0-9]{0,2})([0-9]{0,2})#", $ical_date, $date);
     list($temp, $y, $m, $d, $h, $min, $s) = $date;
     if (!$min) {
         $min = 0;
     }
     if (!$h) {
         $h = 0;
     }
     if (!$d) {
         $d = 0;
     }
     if (!$s) {
         $s = 0;
     }
     // Trap unix dated beofre 1970
     $y = max($y, 1970);
     if ($isUTC) {
         $t = gmJevDate::mktime($h, $min, $s, $m, $d, $y) + 3600 * $offset;
         $result = JevDate::strtotime(gmdate('Y-m-d H:i:s', $t));
     } else {
         $result = JevDate::mktime($h, $min, $s, $m, $d, $y);
     }
     // double check!!
     //list($y1,$m1,$d1,$h1,$min1,$s1)=explode(":",JevDate::strftime('%Y:%m:%d:%H:%M:%S',$result));
     return $result;
 }