cantico / libcaldav

				$icalEnd = new LibCaldav_iCalDate($period->getProperty('DTEND'));

				$icalDuration = $icalStart->DateDifference($icalEnd);

				if ($period->getProperty('RDATE') !== '') {

					$rdates = $this->explodeRules($period->getProperty('RDATE'));

					foreach ($rdates as $rdate) {

						if ($rdate >= $expandStart && $rdate < $expandEnd) {

							$recurrenceDates[$rdate] = $rdate;

						}

					}

				}

				if ($period->getProperty('RRULE') !== '') {

					$rrule = new RRule($icalStart, $period->getProperty('RRULE'));

				// Now we use EXDATE and EXRULE parameters to determine a list

				// of date excluded from the recurrence rule.

				if ($period->getProperty('EXDATE') !== '') {

					$exdates = $this->explodeRules($period->getProperty('EXDATE'));

					foreach ($exdates as $exdate) {

						if ($exdate >= $expandStart && $exdate < $expandEnd) {

							unset($recurrenceDates[$exdate]);

						}

					}

				}

				if ($period->getProperty('EXRULE') !== '') {

					$exrule = new RRule($icalStart, $period->getProperty('EXRULE'));