I really did have good intentions.
I never thought otherwise, not for a minute. It's hard for people, on either side of this issue, to 'learn' the new rules. That's been my experience at least, and I've seen a lot of examples here on SI that seem to back that theory up. Is it true for all? I couldn't say, but I do know that these kinds of misunderstandings do happen in a lot of relationships in R.
I do hope you saw that my post was only some suggestions you could try, and not me attempting to tell you how to 'fix' your marriage.
One thing I've found in my home that seems to work best are the things that aren't said. Using your situation as an example (since we all already know the backdrop):
You know this is a touchy time of year for your H, and for you. You want to do something, for the new memories, in an effort to not sit around dwelling on it, and because it's a nice opportunity to do something as a family. In an effort to not make it seem like you're intentionally trying to make new memories, because maybe that will be seen as you believing that one night out can take the pain away, you propose the evening very casually. Your H says 'no, I have to work'. Maybe he does, or maybe he's just avoiding even thinking about you, the M, the A, any of it. Maybe he wants to preoccupy himself.
You see that as him not wanting to do anything, not wanting to make new memories, not wanting to be 'a family' and that can hurt. It can feel like he won't let you fix things, or even to get those small victories where things a really good for an evening, or an afternoon, or a morning. You become frustrated. Because tensions are high, he immediately sees that as your unhappiness with everything, and not just with the one evening.
Somehow, your invite to dinner and a movie has turned into (for you) him not wanting to spend time with you and (to him) a sign that you're not happy and may leave the marriage.
How in the hell did this happen? This is the opposite of what you were hoping for.
Well, the manner that we say things can matter. You didn't want to bring up the A, so you asked casually. He didn't want to bring it up, so he brushed it all off and decided to work.
As good as your intentions were, they may have been seen as very casual, and as discounting his feelings given the time of year.
What if, instead of asking casually, you had sat down next to him, put your arms around his neck, and said this:
"You know what would be great honey? If you would let me take you and (child) to dinner, and then maybe to a movie. I would really love to spend the evening with my two favorite people, and i was hoping you'd indulge me and let me show you a great time."
or something along those lines. You aren't bringing up the A, but you aren't acting casual about the day. You are saying he's important to you, and that you'd love to do something special.
Of course, you do have to be prepared for him to say no, but if he does, you could say something like:
"Ok honey, I know you need to get the schedule done. How about if I make you your favorite dinner instead so you can finish the schedule, and if time allows we could still go see the movie?"
He'll probably say no to this one (don't go to the trouble, etc.) but you can always insist on this one. I don't think he'll skip dinner.
Obviously, these are only suggestions, but I hope my general thoughts here make sense. I may be very off base, since you know your husband and history, and I don't. If you don't feel this is the right approach for you, maybe you may be able to come up with what might be a better approach?
I would bet anything that your H knows you're trying, and that you're remorseful. I don't want to discount that - it makes a world of difference to a BS - well, to those that I've interacted with - and it is the biggest key to successfully reconciling. The smaller things now can avoid the misunderstanding that, during R, can seem like mountains to overcome.
I think you're doing a really great job at this. I know that it's your H's opinion that matters. I just wanted toss some support your way.