public function IsSegment($segment)
 {
     switch ($segment) {
         case "today":
             return $this->startDate->date() == $this->endDate->date();
         case "week":
             if (CalendarUtil::get_first_day_of_week() == sfTime::MONDAY) {
                 return $this->startDate->format('w') == sfTime::MONDAY && $this->startDate->format('w') == sfTime::SUNDAY;
             }
             return $this->startDate->format('w') == sfTime::SUNDAY && $this->endDate->format('w') == sfTime::SATURDAY;
         case "month":
             return $this->startDate->format('j') == 1 && sfDate::getInstance($this->startDate)->finalDayOfMonth()->format('j') == $this->endDate->format('j');
         case "weekend":
             return $this->startDate->format('w') == sfTime::FRIDAY && $this->endDate->format('w') == sfTime::SUNDAY;
     }
 }