Hope this is helpful! 

use strict; use warnings;
use Date::Calendar::Profiles qw( $Profiles );
use Date::Calendar;

sub to_date {
        my ($d,$m,$y) = split /\//, shift;
        return [$y,$m,$d];
}

sub from_date {
        my $date = shift;
        $date =~ s/(\d{4})(\d{2})(\d{2})/$3\/$2\/$1/;
        return $date;
}

my $calendar  = Date::Calendar->new( $Profiles->{'DE-SN'} );

# first read in the whole file and
# record start and end dates for each employee
my %dates;

# simplified data reading, pls stick to Text::CSV
while (<DATA>) {
        next if /^empl/;
        chomp;
        my( $employee_id,$start_date,$end_date,$total_days) = split /,
+/;
        $dates{$employee_id}{$start_date}{'end'} = $end_date;
        $dates{$employee_id}{$start_date}{'days'} = $total_days;
}

# now we have all the data
# and can process it
for my $employid (sort keys %dates) {
        my $data = $dates{$employid}; 
        for my $startdate (keys %{$data}) {
                my $enddate = $$data{$startdate}{'end'};
                next if $enddate eq 'invalid'; # redundant, see below
                # find next businessday
                my $next = from_date( $calendar->add_delta_workdays(to
+_date($enddate),1) );
                # do we have a record for the next business day ?
                if( exists $$data{$next} ) {
                        # merge two records
                        $$data{$startdate}{'end'} = $$data{$next}{'end
+'};
                        $$data{$startdate}{'days'} += $$data{$next}{'d
+ays'};
                        $$data{$next}{'end'} = 'invalid'; # mark redun
+dant
                }
        }
}

for my $employid (sort keys %dates) {
        my $data = $dates{$employid}; 
        for my $startdate  (keys %{$data}) {
                my $enddate = $$data{$startdate}{'end'};
                next if $enddate eq 'invalid';            
                print "$employid,$startdate,$enddate,";
                print $$data{$startdate}{'days'},"\n";
        }
}
__DATA__
employid, start, stop, total
1234,01/04/2013,05/04/2013,5
1234,08/04/2013,12/04/2013,5
1234,18/04/2013,18/04/2013,1
1234,22/04/2013,22/04/2013,1
1234,23/04/2013,23/04/2013,1
5678,01/01/2013,01/01/2013,1

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In reply to Re^3: Date::Calc and comparing across arrays? by hdb
in thread Date::Calc and comparing across arrays? by rcotten

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