DTSTART)?$this->DTSTART->getDateTime():null; $duration = isset($this->DURATION)?VObject\DateTimeParser::parseDuration($this->DURATION):null; $due = isset($this->DUE)?$this->DUE->getDateTime():null; $completed = isset($this->COMPLETED)?$this->COMPLETED->getDateTime():null; $created = isset($this->CREATED)?$this->CREATED->getDateTime():null; if ($dtstart) { if ($duration) { $effectiveEnd = clone $dtstart; $effectiveEnd->add($duration); return $start <= $effectiveEnd && $end > $dtstart; } elseif ($due) { return ($start < $due || $start <= $dtstart) && ($end > $dtstart || $end >= $due); } else { return $start <= $dtstart && $end > $dtstart; } } if ($due) { return ($start < $due && $end >= $due); } if ($completed && $created) { return ($start <= $created || $start <= $completed) && ($end >= $created || $end >= $completed); } if ($completed) { return ($start <= $completed && $end >= $completed); } if ($created) { return ($end > $created); } return true; } }