#create your destination spreadsheet
my $workbook = Excel::Writer::XLSX->new( 'perl.xlsx' );
my $worksheet = $workbook->add_worksheet(); 

#set date format for rows H and I
my $format = $workbook->add_format( num_format => 'yyyy-mm-dd' );

#create some formatting for dates
$worksheet->set_column('H:I', undef, $format);

# for every spreadsheet...
foreach $file (@files)
{
	do
	{
		#Read the input file		
		$excel = new Spreadsheet::BasicRead($file);
		
		#Get the data from each row		
		while ($dataref = $excel->getNextRow())
		{
			#Write the data into your destination spreadsheet and increment row
			my @data = @$dataref;
			$worksheet->write_row($row, 0, \@data);
			$row++;
		
		}
	}
}