One of my colleagues has a live-in mother's help (more than an au pair, slightly less than a nanny, tho she does do all the cleaning and cook the evening meal). She let it drop the other day that when she has a day off, she docks the mother's help's money as "she's not really working." She doesn't give the poor girl much notice, just says "I'm not working tomorrow" when she gets home at night, so it's not as if she can arrange to do anything else!