use strict;
use warnings;
use POSIX qw(strftime mktime);
use Data::Dumper;

sub ooh {
    my $start = shift;
    my $end   = shift;
    my %wkwk = map {$_ => 1} (1..5); # Mon .. Fri
    my $i;
    my %mns = map{$_=>$i++}qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);
    # Bank holidays
    # We assume they all begin at 00:00:00 and encompas the entire day
    # POSIX::mktime(15, 28, 06, 27, 02, 206);'
    my @bh; 
    while (<DATA>) { # read bank holiday file
        next unless /\d\d?\s+\w\w\w\s+\d{4}/;
        chomp;
        my ($day, $month, $year) = split;
        my $mnth     = $mns{$month};
        my $bh_start = POSIX::mktime(00, 00, 00, $day, $mnth, $year - 1900);
        next if $bh_start < time; # history
        push @bh, $bh_start;
    }
    @bh = sort @bh;
    return sub {
        my $epoch = shift;
        my ($s, $m, $h, $date, $mnth, $yr, $day) = +(localtime $epoch)[0 .. 6];
        print $/;
        print scalar localtime $epoch;
        # Check if we are out of hours, and when next flip is due
        my $valid;
        my $ooh; 
        if ($epoch > $bh[0]) { # its a new bank holiday
            shift @bh;    # rip this page from the calendar
            $ooh = 1; 
            print " Bank Holiday";
        }
        
        if (not $ooh and $wkwk{$day}) { # not a bank hol, is a working day
            my $time = sprintf "%02d:%02d:%02d", $h,$m,$s;
            print " given: $time ";
            if ($time lt $start) { # not out of bed yet
                print "early doors ";
                ($h, $m, $s) = split /:/, $start; 
                $valid = POSIX::mktime($s, $m, $h, $date, $mnth, $yr);
                return 1, $valid;
            } 
            elsif ($time lt $end) { # came in, dreaming of home
                print "within working hours ";
                ($h, $m, $s) = split /:/, $end; 
                $valid = POSIX::mktime($s, $m, $h, $date, $mnth, $yr);
                return 0, $valid;
            }
            else {
                print "g'night";
            }
        }
        else {
            print " weekend" unless $ooh;
        }
        # find next working day 
        my $add = 1;
        ++$add until $wkwk{($day + $add)%7}; 
        print " Next working day is " .($day + $add)%7 . " ";

        # end of day, weekend or hols
        ($h, $m, $s) = split /:/, $start; 
        $valid = POSIX::mktime($s, $m, $h, $date, $mnth, $yr);
        $valid+= $add * (24*60*60);
        return 1, $valid;
    }
}

# get an ooh tester
my $ooh_check = ooh('08:15:00', '17:45:00');

# and run some tests
print join " -> ", 'OOH', $ooh_check->(1382310123);
print join " -> ", 'OOH', $ooh_check->(1359806999);
print join " -> ", 'OOH', $ooh_check->(1360306452);
print join " -> ", 'OOH', $ooh_check->(1381941000);
print join " -> ", 'OOH', $ooh_check->(1360016452);
print join " -> ", 'OOH', $ooh_check->(time);

__DATA__
01 Jan 2012
02 Feb 2013
03 Feb 2014
04 Aug 2013
21 Oct 2013