I am a student working on a thesis. Many of my most important next actions are not so much time or date specific but they do have deadlines. This applies in just general life items too. I'll use a recent example. I needed to buy a bottle of wine for a New Year's eve party... didn't matter when I bought it as long as it was purchased before NY eve. So how do I add this to a my next action list for "errands" (I'm thinking of using MS office as my systems by the way) and not keep the resulting worry in my mind that I need to remember the critical deadline (concerned that ASAP won't be soon enough for example).
Many of my writing projects will be like this as well. I have just finished reading the book and will be going through the collecting and implementing phase in the next few days but this was a niggling concern for me.