I think that parents can basically request whatever they want, and each childminder then has the choice to say "yes", "no" or "I need to think about it."
If I was asked to do five hours a day, I would hope that they would be for set hours, because it then gives the option of having another child for the other hours, or perhaps an extra schoolchild after school. However, it means that parents run the risk of not having the option of necessarily being able to access the remaining hours.
I'm happy to mind term-time only, as I also have holiday-only children to mind. Other minders won't be as keen.
There is no way on this planet that I would guarantee minding for a year. I've been minding for 12 years, and don't intend finishing in the near/far future. I'm pleased to tell parents that I still mind for families that have been with me almost as long. I don't intend to give up until such time that circumstances dictate I should do so - if I feel like stopping for a "non-extreme circumstance", then I think that's my business!!
Mosschops - forget the big stick, I'm going for the whole tree!!!