If you have 2 kids with two different nap schedules, when do you go out with them?

For example: my older son naps once a day around 12:30, but my younger son is on a two nap a day schedule and naps at 9:30 and again at 3. No matter what time of day we go out, it seems like someone is going to miss a nap. My youngest used to be good about napping in his stroller/carseat, but as he gets older, he's more aware of his surroundings and will refuse to nap unless we are home. So I'm wondering what others do in this situation.