I always start the child ful time on the date they are supposed to start, but for the younger ones I do offer the parents a few days a week or just a few initial days before hand to get a feel of the child and have the child get a feel of "mom leaving" and the way things go around here. I don't ever offer the parent to stay for a portion of the day, it will draw out the seperation issues that may take place, I think it can be too confusing to the child, first she stays, then she leaves? The child needs to know right from the start, that just as easy as Mommy left, she also comes back, and he/she if fine while she is gone. The quicker they learn the better off everyone will be!