While I don't dispute the biological aspects of life with ADHD, I also cannot escape the reality of bullshit timelines.
My essence knows, without a shadow of a doubt, that time is cyclical. And just because some person or org says, randomly today, that something NEEDS TO BE COMPLETED by next Thursday or the world ends, doesn't actually change the nature of time.
There have been countless things in life where, as a civilization, we simply allow for trivial shit like this to have actual, life altering consequences. I think we're dumb.
Similar here. For me, if I'm given some arbitrary deadline in the future, it almost guarantees I'm not going to do the thing until the day before, or depending on the task, hours before it's due.
"Hey webguy, we need this report by the end of next week" means I'm not doing it until Friday afternoon, and I have no control over it. Doesn't matter if I try to work on it earlier, just won't happen.
It's having an interest based nervous system. We crave novelty, urgency, interest, and challenge to do anything.