[O] Seeking advice on timeline project

[Alan E. Davis]

I am reconstructing events during over 40 years of my life.   I have a capture template as follows, that isn't working out well:

       ("t" "Timeline " entry (file+headline "Timeline.org" "Timeline Incoming ") "*
   %^{Salient Event}
         %?
        Captured:  %U" :prepend t  :unnarrowed t)

One would rather would like to use a the date entry (calendar display) interface; however, in many cases, I can, at least immediately, only remember the year, or month and year.  Suggestions would be appreciated, how to organize such a project.   And, how to integrate a date with only a year into a timeline, as well as month and year, and specific dates.   

The answer is not obvious to me.

Alan Davis