This is a fairly simple question, but I'll give some context:
Thursday 1 week ago I was in a meeting with my boss, my manager and 1 other colleague (We try to have a somewhat flat structure, though). We discussed a topic and agreed to discuss X next Thursday which would get us ready to discuss Y the meeting following X.
The next week, I hear that the presenting of both X and Y was agreed to be done on Wednesday (not Thursday) and that "that's what was agreed" because it's in their agenda for that day (which was apparently added a day after the meeting).
Now, because of an earlier occurrence where we disagreed on what we had previously agreed I was explicitly writing these agreements down in my notebook, plus my colleague remembers this the same way.
My question is about how I should deal with this. Part of me wants to just say "OK, that's not what we agreed and I have written this down for exactly this reason which I suspected might happen." But that's probably way too passive-aggressive. I feel like I have to defend myself, but that it will be counter-productive when I do that.
I know by now that the best thing I probably could have done is send them an e-mail after a meeting listing my notes and asking for confirmation. But now that I'm in this situation, should I just say nothing and make sure I have X + Y on that day? Or should I stick to what I wrote down for this purpose?