Like others have mentioned already, the Tickler can be part of the solution. Granted, you don't want to carry a horse-carriage of folders with you in these days of the smart phones, but an digital implementation of the facilities the "Tickler" provides might be in order.

As far as I can see from here, many of the most common date and urgency related problems with GTD seem to stem from overlooking the Tickler! The strong and mighty Tickler.