With the one year olds it is pretty much a before and after nap thing which sort of translates into every two hours. Diapers these days can hold a lot more than we give them credit for but that doesn't mean a child should have that wet thing on them for that long. Once they give up the morning nap I check at 9, change at 11, check at 1 before nap changing only those that need it and again at 3:30 after nap. Learned to get them all up and shoes on, beds away, etc. and then do diapers as some pee on waking not while sleeping. Anyone here after 4:30 is checked again unless we are outside and/or the odour dictates otherwise. I plan on 4 per day but always have extra in reserve.