remaining.pl

use 5.020;
use strict;
use warnings;
use DateTime;

my $date = DateTime->now;
my $month = $date->month;

my $days_left = 0;
while ($date->month == $month) {
    if ($date->day_of_week < 6) {
        $days_left++;
    }
    $date->add(days => 1);
}

say "$days_left workdays left in month (including today)";

remaining.raku

my $date = Date.today;
my $month = $date.month;

my $days_left = 0;
while ($date.month == $month) {
    if ($date.day-of-week < 6) {
        $days_left++;
    }
    $date = $date.later(:1day);
}

say "$days_left workdays left in month (including today)";

timings

> time perl remaining.pl        
11 workdays left in month (including today)
perl remaining.pl  0,10s user 0,02s system 99% cpu 0,121 total

> time raku remaining.raku
11 workdays left in month (including today)
raku remaining.raku  0,20s user 0,04s system 135% cpu 0,174 total