If it were me, I would probably charge dbl my daily rate.

however, really think this through. This means that for one week out of the month you would not have a weekend off.

We have a very tough, stressful, high liability job and to not have that down time might effect your love for what you do. Once you start to offer something it's hard to take it away.

I will offer overnight and evening care over the Christmas season. I charge $40 for an evening (picking their child up before 11pm) and I charge between $55 and $70 overnight depending on the hours. I do this around Christmas only as an advantage to having their child with me full time. I've only had one client take me up on the offer and I don't offer it to all of my clients. Just the kids I think I could deal with for an extended period of time.

I would suggest that you offer this service as a "Christmas Holiday" thing.. A chance for parents to make their holiday parties, finish their Christmas shopping. If it works well and it's well received then extend it to one night a month. But at least if you do it as a Christmas special you can stop in January without any one questioning it.