I know I'm not obliged to and that eg if the parent asks me to do the monday next week instead of the Friday then then that's a perk for me as I can still charge for the Friday as that's a contracted day. The parents just don't seem to 'get it' though and take it for granted that I'll just swap days.
I only do after school so it's a matter of £20 or so but still...
The same parent has cut one of my days from Sept so every penny counts.
I suppose the thing is that it actually makes no difference to me if they swap days sometimes, I just don't like it when they assume I will.
What do you do ??