Half Day Program for 20 month old -Oakland or nearby

Our daughter is currently in a nanny share that will end in Sept when the other boy starts preschool. At this point, we hope to find a toddler/preschool program that accepts kids under 2yrs (she will be 20 months) that does half day programming, ideally 3 mornings a week. Ideally, the school would be in Oakland, but we may be able to swing other locations. We would like a play-based setting. Any recommendations would be greatly appreciated!