/**
  * Parse a single cell
  * @param  integer $index
  * @return string
  */
 protected function parseCell($index)
 {
     // If the cell is a date time
     if ($this->cellIsDate($index)) {
         // Parse the date
         return $this->parseDate();
     } elseif ($this->reader->needsCalculation()) {
         // Get calculated value
         return $this->getCalculatedValue();
     } else {
         // Get real value
         return $this->getCellValue();
     }
 }