use strict; 
use warnings;
use DateTime::Event::Recurrence;
use DateTime::SpanSet;
use RRDs;
#
# Set up paths, config data etc...
#

foreach $file ( @array_of_RRD_filenames )
{
    my ( $metric, $interval, $begin, $end ) =
      ( 'AVERAGE', '1800', '-800h', 'now' );
    my $start_span =
      DateTime::Event::Recurrence->weekly( days => [ 1 .. 5 ], hours => 8 );
    my $end_span =
      DateTime::Event::Recurrence->weekly( days => [ 1 .. 5 ], hours => 18 );
    my $span_set = DateTime::SpanSet->from_sets( start_set => $start_span,
                                                 end_set   => $end_span );
    push @opts, $file;
    push @opts, $metric;
    push @opts, "-r $interval";
    push @opts, "-s $begin";
    push @opts, "-e $end";
    my ( $start, $step, $names, $data ) = RRDs::fetch @opts;

##</code><code>##

    my ( $intotal, $outtotal, $i );
    foreach my $value ( @{ $data } )
    {
        $start += $step;
        my ( $minute, $hour, $day, $month, $year ) =
          ( localtime( $start ) )[ 1, 2, 3, 4, 5 ];
        $month += 1;    # Why does localtime give month -1?
        my $dt = DateTime->new(
                                year   => $year,
                                month  => $month,
                                day    => $day,
                                hour   => $hour,
                                minute => $minute
        );
        next unless $span_set->contains( $dt );
        $i++;
        $in_total  += $value->[ 0 ];
        $out_total += $value->[ 1 ];
    }
    # Now go off and work out averages / percentages etc...
    # Build a HoH and exit the for loop.
}
# Output some purty HTML.