One-Line-Per-Day Diary in Org-mode

I keep my diary in a one-line-per-day format. Under this system, each day is represented by a single line using Org-mode's description list syntax:

• Level-1 heading: The Year (e.g., * 2026)
• Level-2 heading: The Week, containing the week number, date range, and a brief weekly highlight (e.g., ** W25 (06-15 - 06-21) - Weekly highlight)
• List items: One line per day, starting with an inactive timestamp and a description separator (::) followed by the day's events.

Here is an example illustrating a complete recent week:

* 2026

** W26 (06-22 - 06-28) - Run 3 times. Mele X1! CPU P1/P2/Multpilers. TPM: LUKS + SSH.

- [2026-06-22 Mon] :: Team dinner.
- [2026-06-23 Tue] :: Running. Daycare fire false alarm. Primes day Mini PC research.
- [2026-06-24 Wed] :: Buy Mele X1.
- [2026-06-25 Thu] :: Running. Benchmark Mele X1. Good single core performance. Emacs startup time ~0.4s.
- [2026-06-26 Fri] :: Bike to pick up. Dinner: YAYOI.
- [2026-06-27 Sat] :: TIL: Performance Copilot (pcp). Arch: migrate to systemd + sd-encrypt. TPM: LUKS unlock + SSH Agent.
- [2026-06-28 Sun] :: Running. Order Square Paper. Termux workaround with non-local network.

At the end of every day, I go to the top of diary.org, add a line for today with the things that worth remembering.

To make writing daily entries frictionless, I use a simple Emacs Lisp helper. I use the following function to insert today's date formatted as an inactive timestamp:

(defun my/insert-current-date ()
  "Insert today's date in Org inactive format."
  (interactive)
  (insert (format-time-string "[%Y-%m-%d %a]")))

I bind this command to a key combination in Org-mode buffers for quick access:

(keymap-set org-mode-map "C-c s d" #'my/insert-current-date)

With this helper, starting a daily log is as simple as typing =- = (or using `M-RET` to start a list item), calling the function, typing ` :: `, and entering the daily highlight.

At the end of each week (Sunday), I pick the things worth highlighting from my daily entries and put them in the weekly heading. This allows me to look back at my past weeks, know what happened, and feel like my days count.

This format has greatly improved both writing and searching:

• Self-Contained Search Results: Since the date and the content of the entry reside on the same line, searching with consult-line or ripgrep returns the full context directly. A search for a keyword like "sourdough" immediately displays the date it happened without needing to check parent headings.
• Compact File Structure: The outline remains clean and fast to fold and navigate, with only weeks and years as headings.
• Lower Friction: Writing a single line per day lowers the cognitive barrier to journaling. Even on busy days, it is easy to jot down a quick summary.

This layout is a lightweight and sustainable way to keep a daily log. By using Org-mode's description lists and automating timestamp insertions, the diary remains clean, highly readable, and easily searchable for years to come.