I also carry some part time clients. I only have one right now, but in the past I've had more. I make sure I let my PT clients know that I need a set schedule at minimum 2 weeks ahead of time emailed to me. And if I don't get it, I bug and bug and bug until I do. I'm not shy about that one. I need to know in case i want to take on other kids on the off days and of course for budgeting.

I always tell them that I do drop in care (although I really don't) and need to have a schedule so I can fill the other spots if nessasary. I also need to know who's coming when so I can plan my big crafts when everyone is here. etc. If they know it's for a good reason they'll fall in line. No one wants their children to miss out.