for(my $i=1; $i < scalar @files; $i++) { #everything same as before until we get to reading the files
    if(-e $files[$i]){
        open IN, "gunzip -c $files[$i]|"
            or die "Can't open $files[$i] for input: $!";

        open OUT, "> $files[$i]_out.txt"
            or die "Can't open $files[$i]_out.txt for output: $!";

        my $firstline = 1;
        my @dt = undef; # date and time
        my @date1 = undef;
        my @date2 = undef;

        if($firstline==1){
            chomp(my $line = <IN>);
            my @header = split(/,/, $line);
            @dt= $header[0] =~ /(\d+)/g;
            @date1 = ($dt[0], $dt[1], $dt[2], $dt[3], $dt[4], $dt[5]);
            @date2 = ($dt[6], $dt[7], $dt[8], $dt[9], $dt[10], $dt[11]);
            $firstline = 0;
        } else {
            <IN> for 1..1
        }
        print OUT "Date\tTime\tDay\tmg\n";

        my $count = 0;
        my $avg_count = 0;

        while(<IN>){                                        #this is where it changes, instead of doing the same thing 12 times I say if the line number (-1 due to header) modulos 12 is 0 then print the average and set it back to 0
            my ($y, $mo, $d, $h, $m, $s) = Add_Delta_DHMS(@date1, 0, 0, $count, 0);
            chomp($_);
            my @line = split(/,/, $_);
            $avg_count += $line[0];
            if((($.)-1)%12 ==0){
                printf OUT qq(%d-%02d-%02d %02d:%02d:%02d), $y, $mo, $d, $h, $m, $s;
                print OUT "\t" . Day_of_Week($y, $mo, $d);
                print OUT "\t" . ($avg_count/12) . "\n";
                $count +=1;
                $avg_count =0;
            }
        }
        close IN;
        close OUT
    }
}