The new Paris Museum Card is for 2, 4, and 6 days. The days are consecutive, but I don't think it begins on Monday, but whenever you begin to use it. Just purchase it at the first museum you go to: http://tinyurl.com/a7uhn

I feel that the Carte Orange is the best transportation card to buy, but that does start on Monday, so if you arrive on the week-end, you'll need something for those days. We usually arrive on a Saturday, so we purchase a Mobilis pass to use on Saturday and Sunday. It works just like the Carte Orange, but you don't have to have a photo for the Mobilis pass. An extra passport photo works just fine for the Carte Orange. For both the Carte Orange and Mobilis passes, Zone 1-2 should be all you need. Here's a website you might find helpful to compare transportation passes: http://tinyurl.com/kftem

Best, Sandy in Illinois