Sounds like you forgot to use utf8::upgrade($from);.

only works when I use locale

No, using unicode semantics is enough.

presuming other changes will be made as well

No, using unicode semantics is enough. 

use HTML::Entities qw( decode_entities );

use locale qw();

my $lc = decode_entities('ä');
my $uc = decode_entities('Ä');

utf8::downgrade($uc);

for (0..2) {
   if ($_ == 0) {
      utf8::downgrade($lc);
      locale->unimport();
      print("Byte Semantics\n");
      print("--------------\n");
   }
   elsif ($_ == 1) {
      utf8::downgrade($lc);
      locale->import();
      print("Locale Semantics\n");
      print("----------------\n");
   }
   elsif ($_ == 2) {
      utf8::upgrade($lc);
      locale->unimport();
      print("Unicode Semantics\n");
      print("-----------------\n");
   }

   if ($lc =~ /^\Q$uc\E\z/) {
      print("case sensitive match\n");
   }
   elsif ($lc =~ /^\Q$uc\E\z/i) {
      print("case insensitive match\n");
   }
   else {
      print("no match\n");
   }

   if ($lc =~ /^[[:alpha:]]\z/) {
      print("[:alpha:]\n");
   } else {
      print("Not [:alpha:]\n");
   }

   if ($lc =~ /^[\p{IsAlpha}]\z/) {
      print("\\p{IsAlpha}\n");
   } else {
      print("Not \\p{IsAlpha}\n");
   }

   print("\n");
}

[download]
Byte Semantics
--------------
no match
Not [:alpha:]
\p{IsAlpha}

Locale Semantics
----------------
no match
Not [:alpha:]
\p{IsAlpha}

Unicode Semantics
-----------------
case insensitive match
[:alpha:]
\p{IsAlpha}

[download]

In reply to Re^5: Date::Manip and German months names (solved) by ikegami
in thread Date::Manip and German months names by almut

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