$day_counter = 0;
foreach $dat_file ( @dat_file ) {
        open RAW, "<$dat_file";
        while ( <RAW> ) {
                next (($day_counter == 0)&&(substr($_,9,2)<17));
                next (($day_counter == 1)&&(substr($_,9,2)>16));
                ($sum,$error) = 0;
                @numbers = split( '\t', $_ );