I decided to give a try to perl6 and I got stuck -- how to parse date in format %Y-%m? Year and month only...? 
perl6 -e  'say Date.new("2019-01-20"); say Date.new("2019-01"); '
2019-01-20
Invalid Date string '2019-01'; use yyyy-mm-dd instead
  in block <unit> at -e line 1

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Edit Let's say I want to check if month is valid. In perl 5 it is so simple: 

use Time::Piece; localtime()->strptime(@ARGV[0], "%Y-%m");

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I don't care about date parsing, I don't look at string at all -- perl5 does that for me. 

bash$    perl -e 'use Time::Piece; localtime()->strptime(@ARGV[0], "%Y
+-%m"); print "ok\n"; '  "2019-01"
ok


bash$    perl -e 'use Time::Piece; localtime()->strptime(@ARGV[0], "%Y
+-%m"); print "ok\n"; '  "2019-77"
Error parsing time at /usr/lib/x86_64-linux-gnu/perl/5.26/Time/Piece.p
+m line 481.

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What is elegant way to do thatn in perl6?

In reply to strptime("%Y-%m") in perl6 by leszekdubiel

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