Fixed typo in example for method week

doc/Type/Dateish.pod

@@ -146,6 +146,6 @@ at the start or end of a year, the week may actually belong to the other year.
     my ($year, $week) = Date.new("2014-12-31").week;
     say $year;      # 2015
     say $week;      # 1
-    say Date.new('2015-01-31').week;        # 2014 5
+    say Date.new('2015-01-31').week;        # 2015 5
 
 =end pod