#! /usr/bin/perl
use strict;
use warnings;
use DateTime;


# functions to set/check for business days
{
  # set defaults; 1-5 (Mo-Fr) are business days
  # see: http://search.cpan.org/perldoc?DateTime#$dt-%3Eday_of_week()
  # for information which number is which day of week
  my %business_day;
  @business_day{1..5} = (1)x5;

  # function to (re)set business days
  sub set_business_days {
    %business_day     = ();
    $business_day($_} = 1    for @_;
  }

  # check if given day of week is a business day
  sub is_business_day {
    my $wday = shift;
    return 1    if $business_day{$wday};
    return 0;
  }
}

# or  1..3 for a shorter week; using 1..5 here is redundant, as they are already predefined
set_business_days( 1..5 );  



my $day1 = DateTime->now( time_zone => 'Europe/Berlin' );

my $add = 7;

while ( $add ) {
        $day1->add( days => 1 );
        $add--  if is_business_day( $day1->wday );
}

print $day1->ymd, $/;