Another thought - think about the 'what happens when he gets home' routine. Is he immediately immersed in the minutiae of household life? Or can he go somewhere quiet?

From my own perspective, after a day of work I need to find a quiet place to regather myself. If he's not getting that at home (I say 'hello' then go into my office for 30 minutes) he may be dawdling on the way to get that space, possibly without realising why...

WEll, he just did it again!! I finally got in touch at 8pm by cell phone (after 3 attempts over an hour's time). He was golfing with a coworker!
I very calmly asked, "Did you forget where you lived again?" I was given the standard, "Yeah."
He said "Well, you weren't home earlier, and I figured you would call when you got home." I had to work late, which is very unusual. It was a very calm, cheerful, conversation...no accusations. I just told him that I wondered where he was, that he should have called, and told him to have a good time.
Oh, and he doesn't get any extra stress from the Household when he gets home. He immediately immerses himself into the world of TV sports! That is a whole different aggravating subject for another time. But, no, we don't attack him with life and family. I think maybe he just gets a little lost on the way home...at least that is how I am starting to think of it, since you so kindly explained that it is like getting distracted. And, I am even beginning to consider...just beginning...to think a little more kindly of the sports addiction!

My NT wife is the one who can forget to call for days at a time on a work road trip. Doesn't bother me at all. She gets locked into a mission, and deviating from it only throws her off in most cases. It's her only even faintly AS-like quality, lol, but it makes sense to me.

I tend to be quite good at calling, but mainly from an organizational standpoint. And there's no issue of whether I'd get any flak - she never nags about anything. Not sure if that's part of it; she would never say, "No, you can't do that tonight, because of..."

Easier on all this with no kids involved, for sure.

Earlier I mentioned that the idea of "retraining" my husband made me feel uncomfortable (at least with the phrasing), but I think now, that maybe I am the one who is being "retrained"! I'm learning how to cope without getting upset over his wierd quirks, and at least attempting to discuss it with him (even though I am highly doubtful that he will actually stick to our "deal" to call if he is going to be late). In the end, I think of course we both need some "training", but it has already made my life a little less stressful to change my own mindset. So, here is to retraining! My own~

If by "retraining" you end up meaning "inflicting psychic pain for coercive purposes", then I appreciate your concern. Also if you end up denying what you're doing.

If you can tell him "this really bothers me, and I hope you can learn to remember, so I will lovingly remind you whenever you forget - and even more lovingly thank you whenever you remember" how would he react?

Oh, I wasn't thinking that deeply, John. It was just that the word "retraining" made me think of a puppy instead of a person.