Do you think that those of us without adequate executive function are on time for things we deem truly important? If you do, then you might want to challenge that notion, and see if that affects your viewpoint.
If you tell me that you'll pick me up at 5pm, but show up at 7pm... I'll be upset most likely. But if you tell me that you'll pick me up at 5pm, but will probably be late, maybe even hours late... I'll get it... And will adjust accordingly (most likely I'll get a ride with someone else if at all time critical).
That's why I find it best to have a reasonable time to aim for, and the people that know me know they will need to be able to accommodate my late arrival. And every once in a while, I might even be on time, though I do consider "5 minutes late" as "on time".
Yes, the people that know me are nice and patient people. That's probably a major reason why I know them in the first place.
"How about I meet you at your place? I often run late and would rather you weren't sitting there waiting for me"
Or you could pick me up at my work; I'll already have to be dressed and out of the house since I'm at work.
I'll quote what I wrote in a reply further below:
> I've missed at least 8 flights in the past decade, have seen only the last 80-90% of many of the films I watched in the cinema, have had to stand in the back for the first act of many stage productions, etc. Seeing me walk, rather than run, through train stations and airports is a rare sight. I don't recall a single multi-day bushwalk I've been on, where I pitched my tent before sunset, or even within 2 hours after it.