As ever, sitting on things for a while always makes things clearer. That is what is so good about this forum.
I've composed a short, very polite, e-mail, which hasn't been sent yet, simply saying that I've been thinking about the dates issue and think it is best if he ensures that he has the necessary dates, etc, himself, as I can't be sure of what he has and doesn't have, and that it isn't right that I become responsible that he has the necessary information. That I of course will answer questions if he has any or needs to check something, clarify things, etc, but that in principle I will assume that he has the same information from the various schools as I do.
I may refine that a bit, but that way he himself can sort whether or not he gets e-mails, texts or whatever. I had already asked all the schools to do that, btw. Two schools I think are fine, it's just the third one that really isn't great on admin. I find myself going in to their office to check things quite frequently.... But if that's their only failing then I'll forgive them, because otherwise they are great.
The unsaid subtext here is that it's a WIFE's job to give him this info, as he has made me redundant then that is no longer my job.....
I will of course inform him if anything drastic happens, if a child ends up in the hospital or whatever; this really is strictly about school dates.