get '/:year/:month/:day' => sub {
    my $year = params->{year};
    my $month = params->{month};
    ...
}

##</code><code>##

get '/*/*/*' => sub {
    my ($year, $month, $day) = splat;
    ...
}

##</code><code>##

sub jan : Regex('^01$') { my ($self, $context, $bar, $baz) = @_; }
sub feb : Regex('^02$') { my ($self, $context, $bar, $baz) = @_; }