Since I follow "Getting Things Done", I get more reminders, not less

As a professor, I have many responsibilities and tasks to take care of, and many of these have deadlines.  To keep track of them, I use an automated "To-Do"-Tracker, which allows me to enter new tasks (and ideas!) quickly, to assign categories and priorities to them, and to mark them as completed when I'm done.  Most importantly, I can attach a "due date" to every task, and tell my tracker to automatically have a task pop up a few days in advance – typically the number of days I will need to complete it.  So far, this works pretty well: When someone asks me whether I'd be available for a task, I can get a good assessment of my commitments (implying the answer is typically "no"); but if I commit to a task, it will almost certainly be done by its deadline.

Now, here's the fun thing.  Since I use this approach, I get way more reminders than before.  Journal editors tell me that my review is due in only five days.  PhD students send me worried letters that I haven't sent out the referral letter yet, due on Friday.  Conference chairs send me friendly reminders that I am an author, yet haven't registered for the conference, due in a week.  Thank you for the reminders – actually, I know all that, as my to-do tracker nicely tells me so, and it is all factored in. Today, I need to work on this paper, this book chapter, this slide deck – all stuff which gets better the earlier it can be reviewed; and I know that the task you remind me off can still wait until due day, or the N days it will take me to complete it.  In 2013, I completed 700+ tasks, and there was only one reminder which was effective (because I had mistyped the completion date).

Overall, I believe that this "just in time" production makes me more effective, as it puts things in the right order (and the right priority).  But then, it apparently strains the nerves of everyone else involved.  Should I set up a rule to complete everything a week before it is due?  Or should I set up a disclaimer of sorts?

(And now back to my "To-Do"-tool: Five days left to complete this paper.  Better start today...)