What time do your toddlers nap?

I have a very small in home day care. Kids are 11 &17 months but have pretty much the same sleep needs. We (parents and me) want to transition them to one nap. They both get up about 7 and dropped off to me around 7:40. They both only made it awake until 11:10-11:15 today. That seems pretty early to have the one nap.