I work shift work and would LOVE to have the flexibility to put DD in for shortened days and only pay for that... but my centre (an ABC) does not have half days and isn't able to give me the flexibility to change around all the time as they have to book children in for the rooms (and the nursery is in high demand). I could get extra days for her easily last year when she was only there 3 days (she is now full time). Also, to get a reduced rate (only available if she doesn't go at all for the day) I have to give 2 weeks notice and it comes out of the 30 something days the government gives you and still contribute to if you get the child care benefit. I hope that makes sense! To make sure DD and I don't spend too much time apart, I drop her off late (which doesn't bother the centre) if I'm on late shift, pick her up early when I'm on an early shift, and do both if I have the day off. Even when I am off, I still take DD for at least a few hours to keep her routine and also because she loves the centre so much she gets feril if she doesn't go!!!!
Anyway, it can't hurt to ask the centre...

MG