I keep my next actions in a Word file. I sort them by context (work, home, etc) then by project. As they are accomplished, I put an X in front of them. At the end of the day, I sort the day's list, the Xs fall to the bottom, and I cut and paste the remaining next actions to the next day, which is in the same word file, right above my just-completed day. What I like about this is I only have to open a single file for all contexts and all days, and that file is searchable.
A possibility just occurred to me. Why not keep my 'tickler file' in that same next action file? If something must occur on a specific day, enter the date, then put the next action item under that date. Eventually, I will get to that date and will find it already populated with time-sensitive next actions. This system would be easy to browse, and, if I were looking for something and wasn't sure where I had put it, easy to search. Is there a reason this would not work?