On the Med cruise in 2011 we had the First Seating at Dinner. On the Med cruise's Disney pushed back the time of the first seating (I believe it was 6:00pm).
They were incredible accommodating for excursions and would take you for dinner up until 7:00pm if they had advance warning. The Dining rooms were use to it and the waiter's were given a list of
DCL excursion times & booking for their table for the next day - so they would check with you the day before about your dining plans.
We made the first seating for every meal except Rome. (But that is a whole other story - we were the last three on the boat (with 10 min. to spare) and I learned a lot about the Port of Citiv.). And if your table was on different excursions that arrived back at different time it didn't even phase them...They also didn't mind if you showed up in your touring clothes - they would rather you eat than miss out altogether.
In terms of the excursions and the time they got back to the boat. Most of the full-day DCL excursions (I would say 90% or more) got back by to the ship around 5:00pm.
We decided to first dining again this time. It gives us a little more flexibility on how to spend the later part of our evening. Especially with a Tween, a toddler & two grandparents!
~Heather~