I don't allow dropoff after 9am because we are off to the parks and other outings and I don't allow pickups until after 3pm to protect the children's naptime. So you are being very kind, but are you sure you want all that disruption in your day? If you do, I would charge a half day rate for the 3 hour day, but a full day rate for the 6 hour day. My maximum day is 9 hours so a half day rate applies to 4.5 hours or less.