My DS wakes up around 6/7am and lasts max 2 hours before a morning nap. It's fairly ok to get him to sleep. He sleeps for 1-2 hours but varies. All of a sudden since Saturday he stays awake around 4-5 hours with no signs of tiredness. Then I take him for a walk to get him for an afternoon nap to get him through to his bedtime at 6/7pm. Is this a normal transition to go longer between naps? He is sleeping fairly good at night so perhaps this is why?