My DS has never napped for more than 30 min at a time (with a timer!). He is still on 3 naps a day. In the morning he does 30 minutes and on good day 40. We used to go for a long walk for the second nap. He might maybe do an hour when he's in his cot at home and between 30-40 min on a walk. Then the 3rd nap falls at 4ish but this one he decides to make a long one and most of the time I have to wake him up at 5 not to mess up bedtime (8). How to make him nap longer in the earlier part of the day? We could then maybe switch to a 2 nap days.