Track changes with version control

You don't need to do this, but it's a nice way to keep track of changes to your data.

git

Start tracking changes:
git init && git add 2017.journal && git commit 2017.journal -m "first commit"

View uncommitted changes: git status, git diff

Commit changes: git commit 2017.journal -m "updates"

View past commits: git log

darcs

darcs init && darcs add 2017.journal && darcs record 2017.journal -m "first commit"

darcs whatsnew, darcs diff

darcs record 2017.journal -m "updates"

darcs log

etc.