I personally think it's a great idea to have an end date for any contract. You can make changes for the renewal next time. I would think that would be easier for parents to understand rather than changing costs or conditions in the middle. Also, if you were going to put an end date on it, it doesn't have to be a year. You could do a transition period for all new children (3-4 months.) If things don't work out for you, you don't have to terminate them, you just don't renew.