log('Converts a time in the form of text to a serial number.'); // Create new PhpSpreadsheet object $spreadsheet = new Spreadsheet(); $worksheet = $spreadsheet->getActiveSheet(); // Add some data $testDates = ['3:15', '13:15', '15:15:15', '3:15 AM', '3:15 PM', '5PM', '9:15AM', '13:15AM', ]; $testDateCount = count($testDates); for ($row = 1; $row <= $testDateCount; ++$row) { $worksheet->setCellValue('A' . $row, $testDates[$row - 1]); $worksheet->setCellValue('B' . $row, '=TIMEVALUE(A' . $row . ')'); $worksheet->setCellValue('C' . $row, '=B' . $row); } $worksheet->getStyle('C1:C' . $testDateCount) ->getNumberFormat() ->setFormatCode('hh:mm:ss'); // Test the formulae for ($row = 1; $row <= $testDateCount; ++$row) { $helper->log('Time String: ' . $worksheet->getCell('A' . $row)->getFormattedValue()); $helper->log('Formula: ' . $worksheet->getCell('B' . $row)->getValue()); $helper->log('Excel TimeStamp: ' . $worksheet->getCell('B' . $row)->getFormattedValue()); $helper->log('Formatted TimeStamp: ' . $worksheet->getCell('C' . $row)->getFormattedValue()); $helper->log(''); }