I got nothin' for you, Sharon. Any advice I might give would mark me immediately as a hypocrite.
The only things I am NOT late for are things that carry immediate and obvious consequences. E.g. when I clock in at work, the computer records the date and time precisely... so I cannot be late or I will get punished for it. Or when I did rowing in college, we had to jump in the bone-chilling water of the canal if we were late... I was never late!! But even in those circumstances, I cut it damn close every single time. There is something in my very being that hates being early for things. It feels like a waste of time for me (I know, ironic isn't it.)
In classes, it was a miracle if I was in my seat (or teaching, if that was my position) more than 15 seconds before the start of class. And turning in papers happened no more than 3 minutes before the deadline. Usually more like 1.5 minutes, if not closer (we are talking about me running across campus with a freshly-printed paper in my hands, trying to get into the building before the campus police locked up for the night... on a regular basis). But I always made it on time.
So, I think in my strange way, I have adapted to being either a hairbreadth away from being late, or just plain being late (especially social occasions). It works for me, for the most part, except that ktspktsp gets frustrated when we are more than 30 minutes late to a party. But I consider 30 minutes late to still be too early, especially in Iceland! So it goes. I work on it, but I still suck at it. But so far nothing has ever gone really wrong as a result of my patterns. Maybe that's why it hasn't changed.