Our nanny has our DS, 18 months, is activities every day and definitely sets a loose schedule of what age appropriate "lesson" she is working on (ie opposites, colors, new signs, etc). It is a better education than DS ever got at daycare. She has independent play and free time scheduled as well. No TV at all ever.
I love having a nanny! She is good for DS and very good for us. We have much more quality time with him as she does all his food prep, laundry and gives him his bath before we get home. And no more rushing around in the morning! I actually have time to read him a book or two before I get dressed in the morning.