we've started at 3hrs, now doing 3 for the first nap and 3.5 for second one. When he woke today from both naps he was fine, playing in the cot, not crying. We went out and he fell asleep, so I let him for about 15/20 mins 5.10/5.25ish. Put him down at 6.30 as he was acting tired, didn't go to sleep till 7, after a little crying in the end, could be hot though...