GarciaPL

my @day_of_week = ('Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday');

sub check_business_day {
    my ($name_of_day) = @_;
    if ( grep( /^$name_of_day$/, @day_of_week ) ) {
        return 1;
    } else {
        return 0;
    }
}

check_business_day($date_time->day_name());