% mojo generate lite_app optional
...
% $EDITOR optional

One could mark the date as optional by giving it a default value of undef:

#!/usr/bin/env perl
use Mojolicious::Lite -signatures;

get '/vote/:value/*when' => { when => undef } => sub ($c) {
    my $value = $c->stash('value');
    my $when  = $c->stash('when');
    $c->render(
        format => 'txt',
        text   => $value . ' ' . ( defined $when ? $when : 'nope' ) . "\n"
    );
};

app->start;

which then allows with-or-without the date queries:

% ./optional get /vote/42 2>/dev/null
42 nope
% ./optional get /vote/42/2020/01/07 2>/dev/null
42 2020/01/07
%