public function render(Varien_Object $row) { $mageTimeStamp = Mage::getModel('core/date')->timestamp(time()); $endDateTimestamp = strtotime($row->getEndDatetime()); $lateDifferenceInSeconds = $mageTimeStamp - $endDateTimestamp; $daysLate = $lateDifferenceInSeconds / (60 * 60 * 24); $daysLateRounded = round($daysLate); return $daysLateRounded; }