1 files changed, 41 insertions, 0 deletions
diff --git a/challenge-138/lubos-kolouch/perl/ch-1.pl b/challenge-138/lubos-kolouch/perl/ch-1.pl
new file mode 100644
index 0000000000..ca8301e52f
--- /dev/null
+++ b/challenge-138/lubos-kolouch/perl/ch-1.pl
@@ -0,0 +1,41 @@
+use strict;
+use warnings;
+use DateTime;
+use List::Util qw/min max/;
+
+sub get_work_days {
+  my $what = shift;
+
+    my $dt_1_1 = DateTime->new(
+      year => $what,
+      month => 1,
+      day => 1);
+
+
+    my $dt_31_12 = DateTime->new(
+      year => $what,
+      month => 12,
+      day => 31);
+
+  
+  my $weeks_in_year = $dt_31_12->week_number;
+  $weeks_in_year += 1 if $dt_1_1->week_number != 1;
+
+  my $result = $weeks_in_year * 5;
+
+  # deduct left over days at the end of the year
+  $result -= max(5-$dt_31_12->day_of_week, 0);
+
+  # deduct days at the beginning of the year
+  $result -= min($dt_1_1->day_of_week-1, 5);
+
+  return $result;
+}
+
+use Test::More;
+
+is(get_work_days(2021), 261);
+is(get_work_days(2020), 262);
+
+
+done_testing;