No matter where I am or what I'm doing, a keybinding quickly flips to today's daypage. From there, keybindings can go back or forward by day or by week. I just jot everything down as I think of it or experience it. (I implement this with emacs/org-mode, but i'm sure you could extend this idea to any configurable text editor)

vimwiki's diary [0] functionality offers exactly the same.

  <leader>w<leader>w

opens a new file under

  ~/vimwiki/diary/

with the current date as a filename.

  <CTRL>-up

and

  <CTRL>-down

jump to the previous/next day.

[0] https://github.com/vimwiki/vimwiki/blob/master/doc/vimwiki.t...