I'm doing the August rotation - just started - and most of these are circuit or endurance workouts, so it's on the same day. Even when I was lifting heavy, I'd either do Cardio in the AM and weights at lunch, or weights in the AM and Cardio at lunch.
My understanding is that the recommendations are 30 minutes of cardio a day for health, 60 to maintain a weight loss and between 60-90 to lose weight. I'm up in the AM too. Only way I can fit it all in and not be disowned by the family. Today's BodyMax/200 jacks/40 push ups took me 104 minutes and was a mix of weights and cardio. I can make time to do this, but it takes some discipline on my end - the snooze button calls me every morning...