Although the lame message leaves everything going nice, I want to get rid of it

Good luck with that :)

rt://Date-Handler/Date::Handler

http://cpansearch.perl.org/src/BBEAUSEJ/Date-Handler-1.2/Handler.pm

sub SetLocale
{
    my $self = shift;
    my $locale = shift;

    croak "No locale passed to SetLocale()" if not defined $locale;

    my $locale_return = POSIX::setlocale(&POSIX::LC_TIME, $locale);

    if( defined $locale_return )
    {
        $self->{locale} = $locale;
        $self->{locale_realname} = $locale_return;

        return $self->{locale};
    }

    print STDERR "Locale $locale does not seem to be implemented on th
+is system, keeping locale ".$self->{locale}."\n";
    return undef;
}
[download]

I suggest as a general idea

$self->WARNING( "Locale $locale does not seem to be implemented on thi
+s system, keeping locale ".$self->{locale}."\n" );

sub WARNING {
  my( $self, $message ) = @_;
  if( $self->{WARNINGS} ){
     print STDERR $message;
  }
}
[download]