Ah, but then what if they meant 9:30 and only gave you a window in case you were early?!
I completely get what you mean, but the mental gymnastics and over thought processing involved with ADHD are, frankly mad.
Should I start aiming for 5 minutes into the window instead then? But then why did I get a window? See, it's all too hard for me!
I'm always ready on time if someone is picking me up, but I often vomit 2-3 times half an hour before from the stress. So it's really not that easy.
So I try to balance my reaction with theirs. If you see what I mean.