I like this. Would love to see the details of how you do it. I too dislike adding dates to entries. My solution has been a vimscript snippet that inserts the current date. I have bound it to <C-l><C-d>
fun! InsertDate()
let l:line = getline('.')
let l:date = strftime('%Y-%m-%d')
call setline('.',strpart(l:line,0,col('.')).l:date.strpart(l:line,col('.')))
endfun
inoremap <C-l><C-d> <ESC>:call InsertDate()<CR>
Let me write a blog post about it. The author of this article in particular might find it useful. Does anyone do something similar?