Ok you guys asked for it
I believe using due date / action dates in any other place than your calendar is a vital misunderstanding of the core GtD principles.
Let's take a look at single next actions first.
Whenever we are down at the next action level we'll arrive sometime at this selection point:
Do it because it is less than 2 minutes
Defer it to a specific time/date (aka schedule it) OR defer it as a next action (do ASAP)
Do it means the following question:
Is it worth the trouble and effort delegating or defering an item because done is done and the other options may take as much or even more time to be organized?
What remains are next actions which take more than 2 minutes for me to get done.
The next question is about delegating:
Do I really have to do this by myself?
What remains are those action I have to do by myself.
Once I've decided to delegate I'll ask myself:
Do I want to follow up?
If no, the item is complete and can be checked off
The next question is about how to follow up:
Is it vital to do the follow up at a specific date?
If yes, I'll SCHEDULE a reminder into the calendar/tickler file (in TR use status scheduled). It'll pop up at that date and I have committed myself to do the followup action at that date.
If no, I'll put it into @waiting for knowing, that the item sits idle in there until the next weekly review. I may then decide to take immediately action, let it sit in waiting for until the next weekly review or SCHEDULE the item now.
The next question is:
How do I defer non delegated and not yet done (2 minute rule) actions?
Defer it to a specific time/date (aka schedule it) OR defer it as a next action (do ASAP)?
I may rephrase this question as
Is it vital for that next action to be done by a specific date or can I let this next action sit undated in its appropriate context until the next weekly review and maybe get done until then?
If yes to vital -> SCHEDULE or If I have committed myself and I don't want it to be committed at all or for that date RENEGOTIATE
If no to vital -> NA list (Do ASAP list in TR)
If I follow this workflow things are where they belong. Done is done, due dated/deadlined actions are in the calendar, the rest in my lists (next actions and @waiting for). There is no need to date anything in those lists, because dated items do not belong into those lists but into the calendar.
Now to the projects
First of all, have I committed myself to get this project done at a given date?
If no, not a single next action from this project will go into the calendar. They will all stay in the undated next actions lists. Why should they go elsewhere?
I'll identify the due date and write it down. For example you may use the project name itself. (Organize my 10th wedding day - 2007/06/27)
I'll identify the milestones (subprojects) if any, and their due dates and write them down (Organize restaurant - 2007/31/05; Organize menu 2007/06/15 and so on)
Now at the (sub)project planning level I'll collect all single next actions. Then I switch to the single action mode and run each and every next action through the above described workflow.
And now comes the key question again:
May any next action sit undated in its appropriate context list and may be done or not until the next weekly review?
Yes -> Na list.
No -> calendar
It is really that simple.
Remember, it it is the weekly review which ties it all together. During the weekly review I decide if a thing has to be moved from status Do ASAP to status SCHEDULED. Putting something into a Next Action list does not mean it has to stay there forever until done. Au contraire. It is in the weekly review when I am in planning mode, where I decide what to do with every single item and every project and subproject. Nothing will be lost and everything will be dealt with appropriately. It works. During the weekly review I'll have to through the next weeks calendar to see upcoming things and I have to decide If I have some work to be done in advance -> calendar. During the weekly review I go through my projects lists and see if any deadlines on projects / subprojects are nearing and if I have to do something about this in advance -> calendar.
There is no need for due dates in Next Action (do ASAP) lists. Remember the main idea behind those Next Action lists is, that you will only come to them unless you have completed anything which is on your calendar for today. So only those items go into such a list which may sit there idle and get not done until the next weekly review without any harm. I personally put everything into these lists which fulfills this rule. But only those next actions and nothing else. I ask myself, can this sit here another week or do I have to become more serious about by scheduling it?
Hope that helps