I purchased a Passe Navigo the last time I was in Paris. I will reload it when I return in May. As I understand it, when I arrive on a Saturday morning, I can reload the pass. But it won't be usable until Monday morning. So I will have to purchase a separate RER B ticket into Paris.
According the the Parisbytrain website, the pass is good until the last Metro run at 0140 Sunday. I think they actually mean 0140 Monday. Yes? I want to use it to take the RER out to CDG on Sunday morning, and I want to make sure the pass is still viable. Thanks.