log('Returns the previous coupon date, before the settlement date for a security.'); // Create new PhpSpreadsheet object $spreadsheet = new Spreadsheet(); $worksheet = $spreadsheet->getActiveSheet(); // Add some data $arguments = [ ['Settlement Date', DateHelper::getDateValue('01-Jan-2011')], ['Maturity Date', DateHelper::getDateValue('25-Oct-2012')], ['Frequency', 4], ]; // Some basic formatting for the data $worksheet->fromArray($arguments, null, 'A1'); $worksheet->getStyle('B1:B2')->getNumberFormat()->setFormatCode('dd-mmm-yyyy'); // Now the formula $worksheet->setCellValue('B6', '=COUPPCD(B1, B2, B3)'); $worksheet->getStyle('B6')->getNumberFormat()->setFormatCode('dd-mmm-yyyy'); $helper->log($worksheet->getCell('B6')->getValue()); $helper->log('COUPPCD() Result is ' . $worksheet->getCell('B6')->getFormattedValue());