From 824f2bb9457bdfde9e2911e1b1baa86a3f7728b9 Mon Sep 17 00:00:00 2001
From: Nils Pukropp <nils@narl.io>
Date: Tue, 20 Oct 2026 23:41:04 +0200
Subject: [PATCH] diary: templates, a calendar, the days either side and this
 day before

A folder called templates at the root of any space holds templates. `:new
<template> [yyyy-mm-dd] [name]` starts a document from one, with {{date}},
{{weekday}}, {{time}} and {{title}} filled in on the server, in
WORKSPACE_TIMEZONE, for the date the document is for. A new diary entry starts
from templates/day when the diary has one, whether it comes from T, o, the
calendar or a capture. Templates are not entries: the calendar, the reminder
and "written today" leave them out.

C (or :cal) shows the diary by month: h/l a day, j/k a week, H/L a month, .
today, and Enter opens the day's entry or starts one dated that day. [d and
]d step to the entry before or after the open one by date, backdated ones
included. The agenda ends with what the diary holds from this day in earlier
years; a 29 February is remembered on the 28th in years without one.

New routes: GET /api/diary/days?month=, GET /api/diary/around/{id} and
GET /api/nodes/{id}/templates. POST /api/nodes takes template_id.
---
 README.md                   |  39 ++-
 src/notify/mod.rs           |  14 +-
 src/routes/boards.rs        |  11 +-
 src/routes/capture.rs       |  15 +-
 src/routes/diary.rs         | 541 ++++++++++++++++++++++++++++++++++++
 src/routes/mod.rs           |   4 +
 src/routes/nodes.rs         |  43 ++-
 web/src/App.svelte          |  63 ++++-
 web/src/lib/Agenda.svelte   |  33 ++-
 web/src/lib/Calendar.svelte | 171 ++++++++++++
 web/src/lib/Help.svelte     |   8 +-
 web/src/lib/api.ts          |  33 +++
 web/src/lib/commands.ts     |  54 +++-
 web/src/lib/store.svelte.ts |  69 ++++-
 14 files changed, 1048 insertions(+), 50 deletions(-)
 create mode 100644 src/routes/diary.rs
 create mode 100644 web/src/lib/Calendar.svelte

diff --git a/README.md b/README.md
index 256fc19..bfcf6f9 100644
--- a/README.md
+++ b/README.md
@@ -98,6 +98,8 @@ it; in the document pane it is that document. In the browse pane:
 | `b` | the board of this space |
 | `t` | the agenda: what is late, due this week, or in hand, on every board |
 | `T` | today's diary entry, started if there is none |
+| `C` | the diary by month (`:cal`) — see [The diary](#the-diary) |
+| `[d` / `]d` | the diary entry before / after the one open, by date |
 | `c` | capture a card into this space's inbox without leaving where you are |
 | `Esc`, `q` | close the document, and its tile when there are several |
 | `h` | up one level in the tree |
@@ -113,7 +115,7 @@ it; in the document pane it is that document. In the browse pane:
 
 Inside the editor the full vim keymap is live — `w`/`b`, `dd`, `ciw`, visual
 mode, macros, `:w` to write. `:help` lists every ex command; the useful ones are
-`:w`, `:wq`, `:q!`, `:new [yyyy-mm-dd]`, `:date`, `:name`, `:share`, `:link`,
+`:w`, `:wq`, `:q!`, `:new [template] [yyyy-mm-dd] [name]`, `:date`, `:name`, `:share`, `:link`,
 `:upload`, `:media`, `:search`, `:backup` and
 `:set novim`. `:name` on its own moves up into the title; `Enter`, `Esc` or `↓`
 there goes back down into the text. In the text, `]]`, `[[` and `gO` walk the
@@ -241,6 +243,32 @@ it stands, `D` sets its due date (`:due` on the line), `H` / `L` send it to
 the list left / right on its board, and `T` writes today's entry. The bar shows `late` and `today` counts
 whenever either is above zero, and the agenda opens by itself once a day when
 something is late or due, so nothing has to be remembered to be looked at.
+Below the cards it lists what the diary holds from this day in earlier years;
+`j` walks on into them and `Enter` opens one. A 29 February is remembered on
+the 28th in the years that have none.
+
+## The diary
+
+The space with the diary role is a journal: each document in it is an entry,
+dated by the day it is about (`:date` changes that). `T` opens today's, `[d`
+and `]d` step to the one before or after by date, and `C` (or `:cal`) shows a
+month: `h` / `l` move a day, `j` / `k` a week, `H` / `L` a month, `.` goes
+back to today, and `Enter` opens the day's entry or starts one dated that day.
+A marked day has an entry, a number says how many. Days are counted in
+`WORKSPACE_TIMEZONE`, the same as the evening reminder.
+
+### Templates
+
+Any space can have a folder called `templates` at its root; every document in
+it is a template. `:new meeting` starts a document from `templates/meeting`,
+`:new meeting 2026-10-20 Budget` dates and names it as well, and Tab completes
+the template names. In a template, `{{date}}` becomes `2026-10-20`,
+`{{weekday}}` `Tuesday`, `{{time}}` `14:05` and `{{title}}` the new document's
+name, all on the clock of `WORKSPACE_TIMEZONE` at the date the document is
+for. A new entry in the diary — from `T`, `o`, the calendar or a capture —
+starts from `templates/day` when the diary has one. The templates are not
+entries, so they are not on the calendar and do not count as having written
+today.
 
 ## Capturing from elsewhere
 
@@ -264,7 +292,7 @@ named by `"space": "<slug>"`, or else of the first space that has a board,
 the same as `:card` outside the board. The first line is the card's title and
 the rest its notes. `"to": "diary"` adds `- 14:05 call the bank` to the end of
 today's entry, in `WORKSPACE_TIMEZONE`, and starts the entry when there is
-none yet. The answer says where it went: `{"to":"card","id":7,"where":"work/backlog"}`.
+none yet, from `templates/day` when the diary has one. The answer says where it went: `{"to":"card","id":7,"where":"work/backlog"}`.
 
 A token opens this one route and nothing else — it reads nothing, not even the
 list of spaces — and only its SHA-256 is kept, the way a share key is. Wrong
@@ -736,13 +764,16 @@ sealed or not.
 | `GET` | `/api/sessions` | every signed-in browser, the one seen last first |
 | `DELETE` | `/api/sessions/{id}` | sign another browser out, and lock the vault |
 | `GET`/`POST` | `/api/spaces` | the spaces / create one |
-| `GET`/`POST` | `/api/nodes` | children (`?parent=`) or search (`?q=`, `?space=`) / create |
+| `GET`/`POST` | `/api/nodes` | children (`?parent=`) or search (`?q=`, `?space=`) / create, from a template with `template_id` |
 | `GET`/`PUT`/`DELETE` | `/api/nodes/{id}` | read / update / delete into the trash, subtree and all — or for good, for something already in it |
 | `GET`/`DELETE` | `/api/trash` | what was deleted, the last first / empty it |
 | `DELETE` | `/api/trash/{id}` | delete one thing in the trash for good |
 | `POST` | `/api/trash/{id}/restore` | back where it was deleted from, or to its space when that folder is gone |
 | `GET` | `/api/spaces/{id}/board` | the lists and cards of one space |
-| `GET` | `/api/agenda` | open cards due within a week or in hand, on every board, and whether the diary has today |
+| `GET` | `/api/agenda` | open cards due within a week or in hand, on every board, whether the diary has today, and its entries `on_this_day` in earlier years |
+| `GET` | `/api/diary/days?month=2026-10` | the diary's entries in a month, each with its local `day` |
+| `GET` | `/api/diary/around/{id}` | the entries before and after a diary entry, by date |
+| `GET` | `/api/nodes/{id}/templates` | the templates of the space the node is in |
 | `POST` | `/api/capture` | `{ text, to: "card" \| "diary", space? }`, with a session or `Authorization: Bearer` a token |
 | `GET`/`POST` | `/api/tokens` | the capture tokens / make one, `{ name }`, answered with the token this once |
 | `DELETE` | `/api/tokens/{id}` | remove a capture token |
diff --git a/src/notify/mod.rs b/src/notify/mod.rs
index 48da8e3..0fb509c 100644
--- a/src/notify/mod.rs
+++ b/src/notify/mod.rs
@@ -461,16 +461,14 @@ fn device_hash(user_agent: &str) -> String {
 /// whether today has been written.
 pub(crate) async fn diary_written(db: &SqlitePool, tz: Tz, day: NaiveDate) -> sqlx::Result<bool> {
     let (start, end) = day_bounds(tz, day);
-    let written: i64 = sqlx::query_scalar(
-        "WITH RECURSIVE tree (id) AS (
-             SELECT id FROM nodes WHERE role = 'diary'
-             UNION ALL
-             SELECT n.id FROM nodes n JOIN tree t ON n.parent_id = t.id
-         )
+    // A template is not an entry, however recently it was written.
+    let written: i64 = sqlx::query_scalar(&format!(
+        "WITH RECURSIVE {}
          SELECT count(*) FROM nodes
-         WHERE kind = 'document' AND id IN (SELECT id FROM tree)
+         WHERE kind = 'document' AND id IN (SELECT id FROM entries)
            AND created_at >= ? AND created_at < ?",
-    )
+        crate::routes::diary::ENTRIES
+    ))
     .bind(start)
     .bind(end)
     .fetch_one(db)
diff --git a/src/routes/boards.rs b/src/routes/boards.rs
index 010a5ce..a4f2dd8 100644
--- a/src/routes/boards.rs
+++ b/src/routes/boards.rs
@@ -140,6 +140,8 @@ pub struct Agenda {
     /// Whether the diary has an entry for today, in the configured timezone —
     /// `None` when there is no diary space to ask about.
     pub diary_today: Option<bool>,
+    /// Diary entries from this day in earlier years, the latest year first.
+    pub on_this_day: Vec<crate::routes::diary::Entry>,
 }
 
 #[derive(Serialize)]
@@ -162,16 +164,21 @@ pub async fn agenda(_: Session, State(state): State<AppState>) -> AppResult<Json
     let has_diary: Option<i64> = sqlx::query_scalar("SELECT id FROM nodes WHERE role = 'diary'")
         .fetch_optional(&state.db)
         .await?;
+    let tz = state.config.mail.timezone;
     let diary_today = match has_diary {
         Some(_) => {
-            let tz = state.config.mail.timezone;
             let today = crate::notify::local_day(tz, crate::now());
             Some(crate::notify::diary_written(&state.db, tz, today).await?)
         }
         None => None,
     };
+    let on_this_day = crate::routes::diary::on_this_day(&state.db, tz, crate::now()).await?;
 
-    Ok(Json(Agenda { cards, diary_today }))
+    Ok(Json(Agenda {
+        cards,
+        diary_today,
+        on_this_day,
+    }))
 }
 
 /// The agenda's cards, due before `horizon` or in hand. Apart from the handler
diff --git a/src/routes/capture.rs b/src/routes/capture.rs
index b24a534..a10fa82 100644
--- a/src/routes/capture.rs
+++ b/src/routes/capture.rs
@@ -14,7 +14,7 @@ use crate::{
     error::{AppError, AppResult},
     routes::{
         boards::{self, CardInput},
-        links, media,
+        diary, links, media,
         nodes::{self, slugify, unique_slug},
         revisions,
     },
@@ -96,7 +96,7 @@ async fn card(db: &SqlitePool, text: &str, space: Option<&str>) -> AppResult<Cap
 
 /// `- 14:05 text`, at the end of today's entry: the first document written
 /// today at the top of the diary, the one `:today` opens. With none yet, the
-/// line starts one, the way `:today` would.
+/// line starts one the way `:today` would, from `templates/day` if there is one.
 async fn diary(db: &SqlitePool, tz: Tz, text: &str, now: i64) -> AppResult<Captured> {
     let line = format!("- {} {}", clock(tz, now), item(text));
 
@@ -134,7 +134,8 @@ async fn diary(db: &SqlitePool, tz: Tz, text: &str, now: i64) -> AppResult<Captu
             id
         }
         None => {
-            let body = format!("{line}\n");
+            let start = diary::day_template(&mut tx, tz, diary, now).await?;
+            let body = appended(start.as_deref().unwrap_or_default(), &line);
             let slug = unique_slug(&mut tx, Some(diary), &slugify(""), None).await?;
             let id: i64 = sqlx::query_scalar(
                 "INSERT INTO nodes (parent_id, kind, name, slug, body, created_at, updated_at)
@@ -203,7 +204,7 @@ fn appended(body: &str, line: &str) -> String {
 }
 
 #[cfg(test)]
-mod tests {
+pub(crate) mod tests {
     use axum::{
         body::Body,
         http::{header, Request, StatusCode},
@@ -218,6 +219,12 @@ mod tests {
 
     const TOKEN: &str = "nwc_a-token-for-the-tests";
 
+    /// A line in the diary in Berlin at `now`, for tests elsewhere: the id of
+    /// the entry it went into.
+    pub(crate) async fn diary_at(db: &sqlx::SqlitePool, text: &str, now: i64) -> i64 {
+        diary(db, Berlin, text, now).await.unwrap().id
+    }
+
     async fn state() -> AppState {
         let state = crate::routes::tests::state_in(".".into()).await;
         sqlx::query("INSERT INTO api_tokens (name, hash, created_at) VALUES ('phone', ?1, 0)")
diff --git a/src/routes/diary.rs b/src/routes/diary.rs
new file mode 100644
index 0000000..4a37bf6
--- /dev/null
+++ b/src/routes/diary.rs
@@ -0,0 +1,541 @@
+//! The diary as a diary rather than a list: the days that have an entry, the
+//! entry before and after the one being read, what was written on this day in
+//! earlier years — and templates, which every space has, but which the diary
+//! is the first to want.
+//!
+//! A day is a local day in `WORKSPACE_TIMEZONE`, the same one the evening
+//! reminder asks about, so the calendar and the mail never disagree.
+
+use axum::{
+    extract::{Path, Query, State},
+    Json,
+};
+use chrono::{Datelike, Months, NaiveDate, TimeZone, Utc};
+use chrono_tz::Tz;
+use serde::{Deserialize, Serialize};
+use sqlx::{Row, SqliteConnection, SqlitePool};
+
+use crate::{
+    auth::Session,
+    error::{AppError, AppResult},
+    notify::{day_bounds, local_day, weekday_name},
+    routes::nodes::{excerpt, path_of, HEAD_CHARS},
+    state::AppState,
+};
+
+/// The folder at the root of a space that holds its templates. Found by name,
+/// as a person would look for it: `role` is for the one diary and the trash.
+pub const TEMPLATES: &str = "templates";
+
+/// The template a new diary entry starts from, when the diary has one.
+pub const DAY: &str = "day";
+
+/// The diary's entries: every document in the diary space except the
+/// templates in its `templates` folder, which are about no day at all.
+/// `WITH RECURSIVE {ENTRIES} SELECT … WHERE kind = 'document' AND id IN
+/// (SELECT id FROM entries)`.
+pub(crate) const ENTRIES: &str = "entries (id) AS (
+         SELECT id FROM nodes WHERE role = 'diary'
+         UNION ALL
+         SELECT n.id FROM nodes n JOIN entries e ON n.parent_id = e.id
+         WHERE NOT (n.kind = 'folder' AND n.slug = 'templates'
+                    AND n.parent_id = (SELECT id FROM nodes WHERE role = 'diary'))
+     )";
+
+#[derive(Serialize)]
+pub struct Template {
+    pub id: i64,
+    pub name: String,
+    pub slug: String,
+}
+
+/// `{{date}}`, `{{weekday}}`, `{{time}}` and `{{title}}` in a template, for a
+/// document dated `at`. The title goes in last, so a title that happens to
+/// contain a placeholder is left as it was typed.
+pub(crate) fn fill(text: &str, tz: Tz, at: i64, title: &str) -> String {
+    let local = Utc
+        .timestamp_opt(at, 0)
+        .single()
+        .unwrap_or_else(Utc::now)
+        .with_timezone(&tz);
+    text.replace("{{date}}", &local.format("%Y-%m-%d").to_string())
+        .replace("{{weekday}}", weekday_name(local.weekday()))
+        .replace("{{time}}", &local.format("%H:%M").to_string())
+        .replace("{{title}}", title)
+}
+
+/// The templates of the space `space_id`, by name.
+pub(crate) async fn templates_of(
+    conn: &mut SqliteConnection,
+    space_id: i64,
+) -> AppResult<Vec<Template>> {
+    let rows = sqlx::query(
+        "SELECT t.id, t.name, t.slug FROM nodes t
+         JOIN nodes f ON f.id = t.parent_id
+         WHERE f.parent_id = ?1 AND f.kind = 'folder' AND f.slug = ?2 AND t.kind = 'document'
+         ORDER BY t.slug",
+    )
+    .bind(space_id)
+    .bind(TEMPLATES)
+    .fetch_all(&mut *conn)
+    .await?;
+    Ok(rows
+        .iter()
+        .map(|row| Template {
+            id: row.get("id"),
+            name: row.get("name"),
+            slug: row.get("slug"),
+        })
+        .collect())
+}
+
+/// The body of the template `id`, filled in for a document called `title`
+/// dated `at`.
+pub(crate) async fn from_template(
+    conn: &mut SqliteConnection,
+    tz: Tz,
+    id: i64,
+    at: i64,
+    title: &str,
+) -> AppResult<String> {
+    let body: Option<String> =
+        sqlx::query_scalar("SELECT body FROM nodes WHERE id = ?1 AND kind = 'document'")
+            .bind(id)
+            .fetch_optional(&mut *conn)
+            .await?;
+    let body = body.ok_or_else(|| AppError::BadRequest("a template is a document".into()))?;
+    Ok(fill(&body, tz, at, title))
+}
+
+/// The diary's `templates/day`, filled in for `at`, when there is one.
+pub(crate) async fn day_template(
+    conn: &mut SqliteConnection,
+    tz: Tz,
+    diary: i64,
+    at: i64,
+) -> AppResult<Option<String>> {
+    let day = templates_of(conn, diary)
+        .await?
+        .into_iter()
+        .find(|template| template.slug == DAY);
+    match day {
+        Some(template) => Ok(Some(from_template(conn, tz, template.id, at, "").await?)),
+        None => Ok(None),
+    }
+}
+
+/// `GET /api/nodes/{id}/templates`: the templates of the space `id` is in.
+pub async fn templates(
+    _: Session,
+    State(state): State<AppState>,
+    Path(id): Path<i64>,
+) -> AppResult<Json<Vec<Template>>> {
+    let path = path_of(&state.db, id).await?;
+    let space = path.first().ok_or(AppError::NotFound)?;
+    let mut conn = state.db.acquire().await?;
+    templates_of(&mut conn, space.id).await.map(Json)
+}
+
+#[derive(Deserialize)]
+pub struct DaysQuery {
+    /// `2026-10`.
+    pub month: String,
+}
+
+/// An entry in the diary, as the calendar and the agenda show it.
+#[derive(Serialize, Debug)]
+pub struct Entry {
+    pub id: i64,
+    pub name: String,
+    /// The local day it is about: `2026-10-20`.
+    pub day: String,
+    pub created_at: i64,
+    /// `diary/untitled`, to open it by.
+    pub path: String,
+    pub excerpt: String,
+}
+
+async fn entries_between(db: &SqlitePool, tz: Tz, start: i64, end: i64) -> AppResult<Vec<Entry>> {
+    let rows = sqlx::query(&format!(
+        "WITH RECURSIVE {ENTRIES}
+         SELECT id, name, created_at, substr(body, 1, {HEAD_CHARS}) AS head FROM nodes
+         WHERE kind = 'document' AND id IN (SELECT id FROM entries)
+           AND created_at >= ?1 AND created_at < ?2
+         ORDER BY created_at, id"
+    ))
+    .bind(start)
+    .bind(end)
+    .fetch_all(db)
+    .await?;
+    let mut entries = Vec::with_capacity(rows.len());
+    for row in rows {
+        let id: i64 = row.get("id");
+        let created_at: i64 = row.get("created_at");
+        entries.push(Entry {
+            id,
+            name: row.get("name"),
+            day: local_day(tz, created_at).format("%Y-%m-%d").to_string(),
+            created_at,
+            path: slug_path(db, id).await?,
+            excerpt: excerpt(row.get("head")),
+        });
+    }
+    Ok(entries)
+}
+
+async fn slug_path(db: &SqlitePool, id: i64) -> AppResult<String> {
+    Ok(path_of(db, id)
+        .await?
+        .iter()
+        .map(|crumb| crumb.slug.as_str())
+        .collect::<Vec<_>>()
+        .join("/"))
+}
+
+/// The entries of one month, from the first of it to the first of the next,
+/// both in the configured timezone.
+async fn month_entries(db: &SqlitePool, tz: Tz, month: &str) -> AppResult<Vec<Entry>> {
+    let first = NaiveDate::parse_from_str(&format!("{month}-01"), "%Y-%m-%d")
+        .map_err(|_| AppError::BadRequest(format!("not a month: {month}, but 2026-10 is")))?;
+    let next = first
+        .checked_add_months(Months::new(1))
+        .ok_or_else(|| AppError::BadRequest(format!("not a month: {month}")))?;
+    entries_between(db, tz, day_bounds(tz, first).0, day_bounds(tz, next).0).await
+}
+
+/// `GET /api/diary/days?month=2026-10`: the entries of a month, for the
+/// calendar to mark its days with.
+pub async fn days(
+    _: Session,
+    State(state): State<AppState>,
+    Query(query): Query<DaysQuery>,
+) -> AppResult<Json<Vec<Entry>>> {
+    month_entries(&state.db, state.config.mail.timezone, &query.month)
+        .await
+        .map(Json)
+}
+
+#[derive(Serialize, Debug, Default)]
+pub struct Around {
+    pub prev: Option<Entry>,
+    pub next: Option<Entry>,
+}
+
+/// The entries either side of `id` by date: `[d` and `]d`.
+async fn around(db: &SqlitePool, tz: Tz, id: i64) -> AppResult<Around> {
+    let at: Option<i64> = sqlx::query_scalar(&format!(
+        "WITH RECURSIVE {ENTRIES}
+         SELECT created_at FROM nodes
+         WHERE id = ?1 AND kind = 'document' AND id IN (SELECT id FROM entries)"
+    ))
+    .bind(id)
+    .fetch_optional(db)
+    .await?;
+    let at = at.ok_or_else(|| AppError::BadRequest("this is not a diary entry".into()))?;
+
+    let step = |before: bool| {
+        let (compare, order) = if before { ("<", "DESC") } else { (">", "ASC") };
+        format!(
+            "WITH RECURSIVE {ENTRIES}
+             SELECT id FROM nodes
+             WHERE kind = 'document' AND id IN (SELECT id FROM entries)
+               AND (created_at {compare} ?1 OR (created_at = ?1 AND id {compare} ?2))
+             ORDER BY created_at {order}, id {order}
+             LIMIT 1"
+        )
+    };
+    let mut found = Around::default();
+    for before in [true, false] {
+        let next: Option<i64> = sqlx::query_scalar(&step(before))
+            .bind(at)
+            .bind(id)
+            .fetch_optional(db)
+            .await?;
+        let Some(next) = next else { continue };
+        let created_at: i64 = sqlx::query_scalar("SELECT created_at FROM nodes WHERE id = ?1")
+            .bind(next)
+            .fetch_one(db)
+            .await?;
+        let entry = entries_between(db, tz, created_at, created_at + 1)
+            .await?
+            .into_iter()
+            .find(|entry| entry.id == next);
+        if before {
+            found.prev = entry;
+        } else {
+            found.next = entry;
+        }
+    }
+    Ok(found)
+}
+
+/// `GET /api/diary/around/{id}`.
+pub async fn around_entry(
+    _: Session,
+    State(state): State<AppState>,
+    Path(id): Path<i64>,
+) -> AppResult<Json<Around>> {
+    around(&state.db, state.config.mail.timezone, id)
+        .await
+        .map(Json)
+}
+
+/// What was written on this day in earlier years, the latest year first.
+/// 29 February comes round only every fourth year; in the others it is
+/// remembered on the 28th, so a leap day is not skipped for three years.
+pub(crate) async fn on_this_day(db: &SqlitePool, tz: Tz, now: i64) -> AppResult<Vec<Entry>> {
+    let first: Option<i64> = sqlx::query_scalar(&format!(
+        "WITH RECURSIVE {ENTRIES}
+         SELECT MIN(created_at) FROM nodes
+         WHERE kind = 'document' AND id IN (SELECT id FROM entries)"
+    ))
+    .fetch_one(db)
+    .await?;
+    let Some(first) = first else {
+        return Ok(Vec::new());
+    };
+
+    let today = local_day(tz, now);
+    let leap = NaiveDate::from_ymd_opt(today.year(), 2, 29).is_some();
+    let late_leap_day = !leap && today.month() == 2 && today.day() == 28;
+    let mut found = Vec::new();
+    for year in (local_day(tz, first).year()..today.year()).rev() {
+        let mut days = vec![NaiveDate::from_ymd_opt(year, today.month(), today.day())];
+        if late_leap_day {
+            days.push(NaiveDate::from_ymd_opt(year, 2, 29));
+        }
+        for day in days.into_iter().flatten() {
+            let (start, end) = day_bounds(tz, day);
+            found.extend(entries_between(db, tz, start, end).await?);
+        }
+    }
+    Ok(found)
+}
+
+/// Whether `id` is the diary space itself, where a new document is an entry.
+pub(crate) async fn is_diary(conn: &mut SqliteConnection, id: i64) -> AppResult<bool> {
+    let role: Option<Option<String>> = sqlx::query_scalar("SELECT role FROM nodes WHERE id = ?1")
+        .bind(id)
+        .fetch_optional(&mut *conn)
+        .await?;
+    Ok(role.flatten().as_deref() == Some(crate::routes::nodes::DIARY))
+}
+
+#[cfg(test)]
+mod tests {
+    use axum::{extract::State, Json};
+    use chrono::TimeZone;
+    use chrono_tz::Europe::Berlin;
+    use sqlx::SqlitePool;
+
+    use super::{around, fill, month_entries, on_this_day};
+    use crate::{auth::Session, routes::nodes::CreateInput, state::AppState};
+
+    fn at(y: i32, mo: u32, d: u32, h: u32, mi: u32) -> i64 {
+        Berlin
+            .with_ymd_and_hms(y, mo, d, h, mi, 0)
+            .earliest()
+            .unwrap()
+            .timestamp()
+    }
+
+    async fn diary(db: &SqlitePool) -> i64 {
+        sqlx::query_scalar("SELECT id FROM nodes WHERE role = 'diary'")
+            .fetch_one(db)
+            .await
+            .unwrap()
+    }
+
+    async fn add(db: &SqlitePool, parent: i64, kind: &str, name: &str, body: &str, at: i64) -> i64 {
+        let slug = crate::routes::nodes::slugify(name);
+        let slug = if slug == "untitled" {
+            format!("e{at}")
+        } else {
+            slug
+        };
+        sqlx::query_scalar(
+            "INSERT INTO nodes (parent_id, kind, name, slug, body, created_at, updated_at)
+             VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?6) RETURNING id",
+        )
+        .bind(parent)
+        .bind(kind)
+        .bind(name)
+        .bind(slug)
+        .bind(body)
+        .bind(at)
+        .fetch_one(db)
+        .await
+        .unwrap()
+    }
+
+    async fn create(state: &AppState, input: CreateInput) -> String {
+        let Json(node) = crate::routes::nodes::create(
+            Session { id: "test".into() },
+            State(state.clone()),
+            Json(input),
+        )
+        .await
+        .unwrap();
+        node.body
+    }
+
+    fn input(parent_id: i64, name: &str, created_at: i64, template_id: Option<i64>) -> CreateInput {
+        CreateInput {
+            parent_id,
+            kind: None,
+            name: name.into(),
+            body: String::new(),
+            created_at: Some(created_at),
+            template_id,
+        }
+    }
+
+    #[test]
+    fn placeholders_keep_to_the_wall_clock_across_daylight_saving() {
+        let text = "{{weekday}} {{date}} {{time}} {{title}}";
+        // Spring: 01:59 is followed by 03:00.
+        assert_eq!(
+            fill(text, Berlin, at(2026, 3, 29, 1, 30), "a"),
+            "Sunday 2026-03-29 01:30 a"
+        );
+        assert_eq!(
+            fill(text, Berlin, at(2026, 3, 29, 1, 30) + 3600, "a"),
+            "Sunday 2026-03-29 03:30 a"
+        );
+        // Autumn: 02:30 happens twice, an hour apart.
+        let first = at(2026, 10, 25, 2, 30);
+        assert_eq!(fill("{{time}}", Berlin, first, ""), "02:30");
+        assert_eq!(fill("{{time}}", Berlin, first + 3600, ""), "02:30");
+        // Before midnight in UTC, after it here.
+        assert_eq!(
+            fill(text, Berlin, at(2026, 10, 21, 0, 30), "{{date}}"),
+            "Wednesday 2026-10-21 00:30 {{date}}"
+        );
+    }
+
+    #[tokio::test]
+    async fn a_new_document_starts_from_its_template_and_an_entry_from_the_day() {
+        let state = crate::routes::tests::state_in(".".into()).await;
+        let db = &state.db;
+        let diary = diary(db).await;
+        let work: i64 = sqlx::query_scalar("SELECT id FROM nodes WHERE slug = 'work'")
+            .fetch_one(db)
+            .await
+            .unwrap();
+        let morning = at(2026, 10, 20, 8, 15);
+
+        // No day template yet: an entry starts empty, as it always has.
+        assert_eq!(create(&state, input(diary, "", morning, None)).await, "");
+
+        let folder = add(db, work, "folder", "templates", "", 0).await;
+        let meeting = add(
+            db,
+            folder,
+            "document",
+            "meeting",
+            "# {{title}}\n{{weekday}} {{date}}\n",
+            0,
+        )
+        .await;
+        let body = create(&state, input(work, "Budget", morning, Some(meeting))).await;
+        assert_eq!(body, "# Budget\nTuesday 2026-10-20\n");
+
+        let folder = add(db, diary, "folder", "templates", "", morning).await;
+        add(db, folder, "document", "day", "## {{weekday}}\n", morning).await;
+        let body = create(&state, input(diary, "", at(2026, 10, 21, 9, 0), None)).await;
+        assert_eq!(body, "## Wednesday\n");
+        // The template is not an entry of the day it was written on.
+        let days = month_entries(db, Berlin, "2026-10").await.unwrap();
+        assert_eq!(days.len(), 2, "{days:?}");
+
+        // Capture that starts a day starts it from the template too.
+        let captured =
+            crate::routes::capture::tests::diary_at(db, "rain", at(2026, 10, 22, 7, 0)).await;
+        let body: String = sqlx::query_scalar("SELECT body FROM nodes WHERE id = ?1")
+            .bind(captured)
+            .fetch_one(db)
+            .await
+            .unwrap();
+        assert_eq!(body, "## Thursday\n\n- 07:00 rain\n");
+    }
+
+    #[tokio::test]
+    async fn a_month_holds_the_days_of_the_timezone() {
+        let state = crate::routes::tests::state_in(".".into()).await;
+        let db = &state.db;
+        let diary = diary(db).await;
+        // An hour apart in UTC, on 31 October both, but a month apart here.
+        let october = add(db, diary, "document", "", "", at(2026, 10, 31, 23, 30)).await;
+        let november = add(db, diary, "document", "", "", at(2026, 11, 1, 0, 30)).await;
+
+        let days = month_entries(db, Berlin, "2026-10").await.unwrap();
+        assert_eq!(days.iter().map(|e| e.id).collect::<Vec<_>>(), [october]);
+        assert_eq!(days[0].day, "2026-10-31");
+        let days = month_entries(db, Berlin, "2026-11").await.unwrap();
+        assert_eq!(days.iter().map(|e| e.id).collect::<Vec<_>>(), [november]);
+        assert_eq!(days[0].day, "2026-11-01");
+        assert!(days[0].path.starts_with("diary/"), "{}", days[0].path);
+        // December rolls over into the next year.
+        assert!(month_entries(db, Berlin, "2026-12")
+            .await
+            .unwrap()
+            .is_empty());
+        for month in ["2026-13", "october", ""] {
+            assert!(month_entries(db, Berlin, month).await.is_err(), "{month}");
+        }
+    }
+
+    #[tokio::test]
+    async fn the_entries_either_side_go_by_date() {
+        let state = crate::routes::tests::state_in(".".into()).await;
+        let db = &state.db;
+        let diary = diary(db).await;
+        let folder = add(db, diary, "folder", "2025", "", 0).await;
+        let older = add(db, folder, "document", "", "", at(2025, 12, 31, 12, 0)).await;
+        let middle = add(db, diary, "document", "", "", at(2026, 1, 2, 12, 0)).await;
+        // Written later, about an earlier day.
+        let backdated = add(db, diary, "document", "", "", at(2026, 1, 1, 12, 0)).await;
+
+        let found = around(db, Berlin, backdated).await.unwrap();
+        assert_eq!(found.prev.map(|e| e.id), Some(older));
+        assert_eq!(found.next.map(|e| e.id), Some(middle));
+        let found = around(db, Berlin, older).await.unwrap();
+        assert!(found.prev.is_none());
+        assert!(around(db, Berlin, middle).await.unwrap().next.is_none());
+        assert!(around(db, Berlin, folder).await.is_err());
+    }
+
+    #[tokio::test]
+    async fn on_this_day_remembers_the_leap_day_in_the_years_without_one() {
+        let state = crate::routes::tests::state_in(".".into()).await;
+        let db = &state.db;
+        let diary = diary(db).await;
+        let leap = add(db, diary, "document", "", "", at(2024, 2, 29, 20, 0)).await;
+        let plain = add(db, diary, "document", "", "", at(2025, 2, 28, 20, 0)).await;
+        add(db, diary, "document", "", "", at(2025, 3, 1, 20, 0)).await;
+        let today = add(db, diary, "document", "", "", at(2027, 2, 28, 8, 0)).await;
+
+        let ids = |found: Vec<super::Entry>| found.into_iter().map(|e| e.id).collect::<Vec<_>>();
+        // 2027 has no 29th, so its 28th remembers both, the latest year first;
+        // its own entry is today's, not a memory.
+        assert_eq!(
+            ids(on_this_day(db, Berlin, at(2027, 2, 28, 9, 0))
+                .await
+                .unwrap()),
+            [plain, leap]
+        );
+        // A leap year has a 29th of its own to remember the leap day on.
+        assert_eq!(
+            ids(on_this_day(db, Berlin, at(2028, 2, 28, 9, 0))
+                .await
+                .unwrap()),
+            [today, plain]
+        );
+        assert_eq!(
+            ids(on_this_day(db, Berlin, at(2028, 2, 29, 9, 0))
+                .await
+                .unwrap()),
+            [leap]
+        );
+    }
+}
diff --git a/src/routes/mod.rs b/src/routes/mod.rs
index 9a430ef..fb3cb17 100644
--- a/src/routes/mod.rs
+++ b/src/routes/mod.rs
@@ -1,6 +1,7 @@
 pub mod backup;
 pub mod boards;
 pub mod capture;
+pub mod diary;
 pub mod export;
 pub mod import;
 pub mod inspect;
@@ -56,6 +57,8 @@ pub fn api_router(max_upload: usize) -> Router<AppState> {
         .route("/spaces", get(nodes::spaces).post(nodes::create_space))
         .route("/spaces/overview", get(nodes::overview))
         .route("/agenda", get(boards::agenda))
+        .route("/diary/days", get(diary::days))
+        .route("/diary/around/{id}", get(diary::around_entry))
         .route("/capture", post(capture::capture))
         .route("/spaces/{id}/board", get(boards::board))
         .route("/spaces/{id}/lists", post(boards::create_list))
@@ -76,6 +79,7 @@ pub fn api_router(max_upload: usize) -> Router<AppState> {
         .route("/nodes/{id}", delete(nodes::remove))
         .route("/nodes/{id}/revisions", get(revisions::list))
         .route("/nodes/{id}/backlinks", get(links::backlinks))
+        .route("/nodes/{id}/templates", get(diary::templates))
         .route("/nodes/{id}/revisions/{rev}", get(revisions::get))
         .route("/nodes/move", post(nodes::move_many))
         .route("/nodes/{id}/move", post(nodes::move_node))
diff --git a/src/routes/nodes.rs b/src/routes/nodes.rs
index 7b7482d..5c25174 100644
--- a/src/routes/nodes.rs
+++ b/src/routes/nodes.rs
@@ -10,7 +10,7 @@ use sqlx::{Row, SqliteConnection, SqlitePool};
 use crate::{
     auth::Session,
     error::{AppError, AppResult},
-    routes::{links, media, revisions, trash},
+    routes::{diary, links, media, revisions, trash},
     state::AppState,
 };
 
@@ -148,6 +148,10 @@ pub struct CreateInput {
     /// Optional override so a document can be backdated to the day it is about.
     #[serde(default)]
     pub created_at: Option<i64>,
+    /// A document to start from, its placeholders filled in for this one. A
+    /// new entry in the diary starts from `templates/day` without being asked.
+    #[serde(default)]
+    pub template_id: Option<i64>,
 }
 
 #[derive(Deserialize)]
@@ -208,7 +212,7 @@ const MOVE_AT_ONCE: usize = 1000;
 
 /// How much of a body the list query reads. Comfortably more than an excerpt
 /// needs, and a rounding error next to documents that run to thousands of words.
-const HEAD_CHARS: usize = 1024;
+pub(crate) const HEAD_CHARS: usize = 1024;
 const EXCERPT_CHARS: usize = 180;
 
 /// The columns every list query selects, so a row always converts the same way.
@@ -223,7 +227,7 @@ const SUMMARY_COLUMNS: &str =
 /// A short, plain-ish preview of the body for the list pane. `head` is only the
 /// leading `HEAD_CHARS` of the document, so truncation is inferred from its
 /// length rather than measured against the whole body.
-fn excerpt(head: &str) -> String {
+pub(crate) fn excerpt(head: &str) -> String {
     let flat: String = head
         .lines()
         .map(str::trim)
@@ -626,6 +630,31 @@ pub async fn create(
     let created_at = input.created_at.unwrap_or(now);
     let slug = unique_slug(&mut tx, Some(input.parent_id), &slugify(&input.name), None).await?;
 
+    let tz = state.config.mail.timezone;
+    let name = input.name.trim();
+    let body = match input.template_id {
+        Some(_) if kind != DOCUMENT => {
+            return Err(AppError::BadRequest(
+                "only a document starts from a template".into(),
+            ));
+        }
+        Some(_) if !input.body.is_empty() => {
+            return Err(AppError::BadRequest(
+                "a document starts from a template or from a body, not both".into(),
+            ));
+        }
+        Some(template) => diary::from_template(&mut tx, tz, template, created_at, name).await?,
+        None if kind == DOCUMENT
+            && input.body.is_empty()
+            && diary::is_diary(&mut tx, input.parent_id).await? =>
+        {
+            diary::day_template(&mut tx, tz, input.parent_id, created_at)
+                .await?
+                .unwrap_or_default()
+        }
+        None => input.body,
+    };
+
     let id: i64 = sqlx::query(
         "INSERT INTO nodes (parent_id, kind, name, slug, body, created_at, updated_at)
          VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7)
@@ -633,17 +662,17 @@ pub async fn create(
     )
     .bind(input.parent_id)
     .bind(kind)
-    .bind(input.name.trim())
+    .bind(name)
     .bind(&slug)
-    .bind(&input.body)
+    .bind(&body)
     .bind(created_at)
     .bind(now)
     .fetch_one(&mut *tx)
     .await?
     .get("id");
 
-    media::link_to_node(&mut tx, id, &input.body).await?;
-    links::index(&mut tx, id, &input.body).await?;
+    media::link_to_node(&mut tx, id, &body).await?;
+    links::index(&mut tx, id, &body).await?;
     // A `[[link]]` written before the document it names now finds it.
     links::follow(&mut tx, id).await?;
     tx.commit().await?;
diff --git a/web/src/App.svelte b/web/src/App.svelte
index 0f800d2..9857e9b 100644
--- a/web/src/App.svelte
+++ b/web/src/App.svelte
@@ -2,6 +2,7 @@
   import { cycleTile, focusTile, followLink, hooks, runCommand } from './lib/commands'
   import { embedSnippet } from './lib/markdown'
   import Agenda from './lib/Agenda.svelte'
+  import Calendar from './lib/Calendar.svelte'
   import Bar from './lib/Bar.svelte'
   import Board from './lib/Board.svelte'
   import CommandLine from './lib/CommandLine.svelte'
@@ -25,7 +26,7 @@
   import Sidebar from './lib/Sidebar.svelte'
   import StatusBar from './lib/StatusBar.svelte'
   import { workspace } from './lib/store.svelte'
-  import { dwindle, neighbour, type Direction } from './lib/util'
+  import { dwindle, formatDay, neighbour, type Direction } from './lib/util'
 
   /*
    * A share link is /s/<token>#<key>. The fragment never leaves the browser, so
@@ -292,14 +293,18 @@
     return false
   }
 
-  /** The agenda's keys: j/k down the list, Enter to the card, Space finishes it. */
+  /**
+   * The agenda's keys: j/k down the list, Enter to the card, Space finishes it.
+   * Past the cards the cursor walks on into what was written on this day.
+   */
   function agendaKey(event: KeyboardEvent): boolean {
     const cards = workspace.agendaCards
     const card = cards[workspace.agendaCursor]
+    const past = workspace.agenda.on_this_day[workspace.agendaCursor - cards.length]
     switch (event.key) {
       case 'j':
       case 'ArrowDown':
-        workspace.agendaCursor = Math.min(workspace.agendaCursor + 1, Math.max(cards.length - 1, 0))
+        workspace.agendaCursor = Math.min(workspace.agendaCursor + 1, Math.max(cards.length + workspace.agenda.on_this_day.length - 1, 0))
         return true
       case 'k':
       case 'ArrowUp':
@@ -307,6 +312,10 @@
         return true
       case 'Enter':
         if (card) void workspace.guard(() => workspace.goToCard(card))
+        else if (past) {
+          workspace.overlay = 'none'
+          void workspace.guard(() => workspace.openPath(past.path))
+        }
         return true
       case ' ':
         if (card) void workspace.guard(() => workspace.finishCard(card))
@@ -335,6 +344,35 @@
     }
   }
 
+  /** The calendar's keys: h/l a day, j/k a week, H/L a month, Enter to the day. */
+  function calendarKey(event: KeyboardEvent): boolean {
+    const step: Record<string, [number, number]> = {
+      h: [-1, 0], ArrowLeft: [-1, 0], l: [1, 0], ArrowRight: [1, 0],
+      k: [-7, 0], ArrowUp: [-7, 0], j: [7, 0], ArrowDown: [7, 0],
+      H: [0, -1], L: [0, 1],
+    }
+    if (event.key in step) {
+      const [days, months] = step[event.key]
+      void workspace.guard(() => workspace.moveCalendar(days, months))
+      return true
+    }
+    switch (event.key) {
+      case '.':
+        workspace.calendarDay = formatDay(Math.floor(Date.now() / 1000))
+        void workspace.guard(() => workspace.loadCalendar())
+        return true
+      case 'Enter':
+        void workspace.guard(() => workspace.openCalendarDay()).then(() => hooks.focusEditor())
+        return true
+      case 'C':
+      case 'q':
+        workspace.overlay = 'none'
+        return true
+      default:
+        return false
+    }
+  }
+
   /** `gO`'s list: j/k down the headings, Enter to the one picked. */
   function outlineKey(event: KeyboardEvent): boolean {
     const last = Math.max(workspace.outline.length - 1, 0)
@@ -675,6 +713,12 @@
         return
       }
     }
+    if (workspace.overlay === 'calendar' && listening && !event.ctrlKey && !event.metaKey && !event.altKey) {
+      if (calendarKey(event)) {
+        event.preventDefault()
+        return
+      }
+    }
     if (workspace.overlay === 'outline' && listening && !event.ctrlKey && !event.metaKey && !event.altKey) {
       if (outlineKey(event)) {
         event.preventDefault()
@@ -769,6 +813,11 @@
       void runCommand('today')
       return
     }
+    if (key === 'C') {
+      event.preventDefault()
+      void runCommand('cal')
+      return
+    }
 
     if (workspace.view === 'board') {
       if (previous === 'g' && key === 'g') {
@@ -847,6 +896,12 @@
       if (!reading || !hooks.scrollWide(amount)) workspace.say('nothing wider than the column in view', 'error')
       return
     }
+    // `[d` / `]d`: the diary entry of the day before or after, by its date.
+    if ((previous === '[' || previous === ']') && key === 'd') {
+      event.preventDefault()
+      void workspace.guard(() => workspace.stepEntry(previous === '[' ? -1 : 1))
+      return
+    }
     if ((previous === ']' && key === ']') || (previous === '[' && key === '[')) {
       event.preventDefault()
       // Past the last heading there is still the end, as in vim.
@@ -1112,7 +1167,7 @@
       <!-- svelte-ignore a11y_click_events_have_key_events, a11y_no_static_element_interactions, a11y_no_noninteractive_tabindex -->
       <div class="overlay" tabindex="-1" bind:this={overlayEl} onclick={(e) => e.target === e.currentTarget && (workspace.overlay = 'none')}
       >
-        {#if workspace.overlay === 'help'}<Help />{:else if workspace.overlay === 'overview'}<Overview />{:else if workspace.overlay === 'agenda'}<Agenda />{:else if workspace.overlay === 'actions'}<Actions />{:else if workspace.overlay === 'verify'}<Verify />{:else if workspace.overlay === 'outline'}<Headings />{:else if workspace.overlay === 'trash'}<Trash />{:else if workspace.overlay === 'history'}<History />{:else if workspace.overlay === 'backlinks'}<Backlinks />{:else}<MediaBrowser />{/if}
+        {#if workspace.overlay === 'help'}<Help />{:else if workspace.overlay === 'overview'}<Overview />{:else if workspace.overlay === 'agenda'}<Agenda />{:else if workspace.overlay === 'actions'}<Actions />{:else if workspace.overlay === 'verify'}<Verify />{:else if workspace.overlay === 'outline'}<Headings />{:else if workspace.overlay === 'trash'}<Trash />{:else if workspace.overlay === 'history'}<History />{:else if workspace.overlay === 'backlinks'}<Backlinks />{:else if workspace.overlay === 'calendar'}<Calendar />{:else}<MediaBrowser />{/if}
       </div>
     {/if}
   </div>
diff --git a/web/src/lib/Agenda.svelte b/web/src/lib/Agenda.svelte
index 64e9b5c..63cc575 100644
--- a/web/src/lib/Agenda.svelte
+++ b/web/src/lib/Agenda.svelte
@@ -5,7 +5,7 @@
    * had today yet. The keys live in App.svelte with the others; this draws
    * and lets a pointer do the same.
    */
-  import type { AgendaCard } from './api'
+  import type { AgendaCard, DiaryEntry } from './api'
   import { workspace } from './store.svelte'
   import { runCommand } from './commands'
   import Icon from './Icon.svelte'
@@ -23,6 +23,12 @@
     sheet?.querySelector<HTMLElement>(`[data-index="${index}"]`)?.scrollIntoView({ block: 'nearest' })
   })
 
+  /** An entry from an earlier year, in place in the diary. */
+  function open(entry: DiaryEntry) {
+    workspace.overlay = 'none'
+    void workspace.guard(() => workspace.openPath(entry.path))
+  }
+
   /** Where a card sits in the walked order, across the groups. */
   function indexOf(card: AgendaCard) {
     return workspace.agendaCards.findIndex((c) => c.id === card.id)
@@ -80,10 +86,33 @@
     <p class="clear">nothing late, nothing due this week, nothing in hand. <span class="kbd">c</span> captures the next thing.</p>
   {/each}
 
+  {#if workspace.agenda.on_this_day.length}
+    <section class="past">
+      <h2>on this day <span class="n">{workspace.agenda.on_this_day.length}</span></h2>
+      <ul>
+        {#each workspace.agenda.on_this_day as entry, at (entry.id)}
+          {@const index = total + at}
+          <li>
+            <button
+              class="row"
+              class:at={index === workspace.agendaCursor}
+              data-index={index}
+              onclick={() => open(entry)}
+              onpointerenter={() => (workspace.agendaCursor = index)}
+            >
+              <span class="text">{entry.name.trim() || entry.excerpt || 'untitled'}</span>
+              <span class="due">{entry.day.slice(0, 4)}</span>
+            </button>
+          </li>
+        {/each}
+      </ul>
+    </section>
+  {/if}
+
   <footer class="label">
     <span class="kbd">j</span><span class="kbd">k</span> move
     <span class="gap"></span>
-    <span class="kbd">↵</span> to its board
+    <span class="kbd">↵</span> open
     <span class="gap"></span>
     <span class="kbd">␣</span> done
     <span class="gap"></span>
diff --git a/web/src/lib/Calendar.svelte b/web/src/lib/Calendar.svelte
new file mode 100644
index 0000000..8de51c4
--- /dev/null
+++ b/web/src/lib/Calendar.svelte
@@ -0,0 +1,171 @@
+<script lang="ts">
+  /*
+   * `C`: the diary by month, the way a paper one is leafed through — the days
+   * written in marked, the day under the cursor shown below. The keys live in
+   * App.svelte with the others; this draws and lets a pointer do the same.
+   */
+  import { workspace } from './store.svelte'
+  import { formatDay } from './util'
+
+  const WEEKDAYS = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun']
+
+  const month = $derived(workspace.calendarDay.slice(0, 7))
+  const title = $derived.by(() => {
+    const [y, m] = month.split('-').map(Number)
+    return new Date(y, m - 1, 1).toLocaleDateString(undefined, { month: 'long', year: 'numeric' }).toLowerCase()
+  })
+
+  /** The month's days in weeks from Monday, with blanks before the first. */
+  const cells = $derived.by(() => {
+    const [y, m] = month.split('-').map(Number)
+    const lead = (new Date(y, m - 1, 1).getDay() + 6) % 7
+    const length = new Date(y, m, 0).getDate()
+    const days: (string | null)[] = Array(lead).fill(null)
+    for (let d = 1; d <= length; d++) days.push(`${month}-${String(d).padStart(2, '0')}`)
+    return days
+  })
+
+  const today = $derived(formatDay(Math.floor(Date.now() / 1000)))
+  const counts = $derived(
+    workspace.calendarEntries.reduce((all, entry) => all.set(entry.day, (all.get(entry.day) ?? 0) + 1), new Map<string, number>()),
+  )
+  const chosen = $derived(workspace.calendarEntries.filter((entry) => entry.day === workspace.calendarDay))
+
+  function pick(day: string) {
+    workspace.calendarDay = day
+    void workspace.guard(() => workspace.openCalendarDay())
+  }
+</script>
+
+<div class="sheet">
+  <header>
+    <span class="label rule"><span class="marker"></span><span class="title">{title}</span> {workspace.calendarEntries.length} entries</span>
+    <button onclick={() => workspace.guard(() => workspace.moveCalendar(0, -1))} aria-label="previous month">‹</button>
+    <button onclick={() => workspace.guard(() => workspace.moveCalendar(0, 1))} aria-label="next month">›</button>
+    <button onclick={() => (workspace.overlay = 'none')}>esc</button>
+  </header>
+
+  <ol class="grid">
+    {#each WEEKDAYS as weekday (weekday)}
+      <li class="weekday label">{weekday}</li>
+    {/each}
+    {#each cells as day, index (day ?? `blank-${index}`)}
+      {#if day}
+        <li>
+          <button
+            class="day"
+            class:at={day === workspace.calendarDay}
+            class:today={day === today}
+            class:written={counts.has(day)}
+            onclick={() => pick(day)}
+          >
+            <span class="n">{Number(day.slice(8))}</span>
+            {#if (counts.get(day) ?? 0) > 1}<span class="many">{counts.get(day)}</span>{:else if counts.has(day)}<span class="dot"></span>{/if}
+          </button>
+        </li>
+      {:else}
+        <li></li>
+      {/if}
+    {/each}
+  </ol>
+
+  <section class="chosen">
+    <h2>{workspace.calendarDay}</h2>
+    {#each chosen as entry (entry.id)}
+      <p class="entry"><span class="name">{entry.name.trim() || entry.excerpt || 'untitled'}</span></p>
+    {:else}
+      <p class="none">nothing written — <span class="kbd">↵</span> starts it</p>
+    {/each}
+  </section>
+
+  <footer class="label">
+    <span class="kbd">h</span><span class="kbd">l</span> day
+    <span class="gap"></span>
+    <span class="kbd">j</span><span class="kbd">k</span> week
+    <span class="gap"></span>
+    <span class="kbd">H</span><span class="kbd">L</span> month
+    <span class="gap"></span>
+    <span class="kbd">.</span> today
+    <span class="gap"></span>
+    <span class="kbd">↵</span> open
+    <span class="gap"></span>
+    <span class="kbd">C</span><span class="kbd">esc</span> close
+  </footer>
+</div>
+
+<style>
+  .sheet {
+    display: flex;
+    flex-direction: column;
+    gap: 16px;
+    width: min(100%, 60ch);
+    max-height: 100%;
+    overflow-y: auto;
+    background: color-mix(in oklab, var(--hull) 97%, transparent);
+    border: 1px solid var(--surface-alt);
+    border-radius: var(--frame-radius);
+    padding: 20px 24px;
+  }
+
+  header { display: flex; align-items: center; gap: 12px; }
+  header .label { flex: 1; }
+  header .marker { background: var(--light); }
+  header .title { color: var(--light); }
+
+  .grid {
+    display: grid;
+    grid-template-columns: repeat(7, 1fr);
+    gap: 4px;
+    list-style: none;
+    margin: 0;
+    padding: 0;
+  }
+  .weekday { text-align: center; font-size: 10px; color: var(--muted); }
+
+  .day {
+    position: relative;
+    display: grid;
+    place-items: center;
+    width: 100%;
+    aspect-ratio: 1.4;
+    padding: 0;
+    border: 1px solid transparent;
+    border-radius: var(--radius-s);
+    font-size: 13px;
+    letter-spacing: 0;
+    color: var(--subtle);
+    font-variant-numeric: tabular-nums;
+  }
+  .day:active { transform: none; }
+  .day.written { color: var(--fg); }
+  .day.today { border-color: var(--rim); }
+  .day.at { background: var(--light); color: var(--ink); }
+  .dot, .many { position: absolute; bottom: 4px; }
+  .dot { width: 5px; height: 5px; border-radius: 999px; background: var(--light); }
+  .many { font-size: 9px; color: var(--light); }
+  .day.at :is(.dot) { background: var(--ink); }
+  .day.at .many { color: var(--ink); }
+
+  .chosen h2 {
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    margin: 0 0 6px;
+    font-size: 10px;
+    font-weight: 400;
+    letter-spacing: 0.22em;
+    color: var(--muted);
+  }
+  .chosen h2::after { content: ''; height: 1px; flex: 1; background: var(--overlay); }
+  .entry, .none { margin: 2px 0; font-size: 13px; }
+  .entry .name { font-family: var(--font-sans); font-size: 14px; color: var(--fg); }
+  .none { color: var(--subtle); }
+
+  footer { display: flex; flex-wrap: wrap; align-items: center; gap: 4px; font-size: 10px; }
+  footer .kbd { margin-right: 2px; }
+  footer .gap { width: 14px; }
+
+  @media (max-width: 767px), (pointer: coarse) {
+    footer { display: none; }
+  }
+</style>
diff --git a/web/src/lib/Help.svelte b/web/src/lib/Help.svelte
index 9324eca..4ba387b 100644
--- a/web/src/lib/Help.svelte
+++ b/web/src/lib/Help.svelte
@@ -32,7 +32,9 @@
     ['M', 'pick up the whole folder — again puts it all back'],
     ['Ctrl / Shift-click', 'pick a row up · every row up to it — drag them onto a folder'],
     ['t', 'agenda — late, due this week, in hand, on every board'],
-    ['T', "today's diary entry, started if there is none"],
+    ['T', "today's diary entry, started if there is none — from templates/day when the diary has one"],
+    ['C', 'the diary by month: h/l a day, j/k a week, H/L a month, . today, Enter opens or starts the day'],
+    ['[d / ]d', 'the diary entry before / after the one open, by date'],
     ['Ctrl-P', 'find anything, in every space — Enter goes to the result lit'],
     ['b', "open this space's board"],
     ['c', "capture a card into this space's inbox, without leaving here"],
@@ -73,8 +75,8 @@
   ]
 
   const agendaKeys: [string, string][] = [
-    ['j / k', 'down / up the cards'],
-    ['Enter', 'to the card, on its own board'],
+    ['j / k', 'down / up the cards, then what was written on this day in earlier years'],
+    ['Enter', 'to the card, on its own board — or to the entry'],
     ['Space', 'done, where it stands'],
     ['D', 'due date: fri, tm, +3d … — :due on the line'],
     ['H / L', 'to the list left / right on its board'],
diff --git a/web/src/lib/api.ts b/web/src/lib/api.ts
index 75a45d4..4f3cdab 100644
--- a/web/src/lib/api.ts
+++ b/web/src/lib/api.ts
@@ -183,6 +183,27 @@ export interface Agenda {
   cards: AgendaCard[]
   /** Whether the diary has an entry today; null when there is no diary. */
   diary_today: boolean | null
+  /** Diary entries from this day in earlier years, the latest year first. */
+  on_this_day: DiaryEntry[]
+}
+
+/** A diary entry, by the local day it is about. */
+export interface DiaryEntry {
+  id: number
+  name: string
+  /** `2026-10-20`, in the server's timezone. */
+  day: string
+  created_at: number
+  /** `diary/untitled`, to open it by. */
+  path: string
+  excerpt: string
+}
+
+/** A document in a space's `templates` folder. */
+export interface Template {
+  id: number
+  name: string
+  slug: string
 }
 
 export interface BoardList {
@@ -433,8 +454,20 @@ export const api = {
     name?: string
     body?: string
     created_at?: number
+    /** Start from this document, its `{{date}}` and the rest filled in. */
+    template_id?: number
   }) => request<WorkspaceNode>('/nodes', { method: 'POST', body: body(input) }),
 
+  /** The templates of the space `id` is in. */
+  templates: (id: number) => request<Template[]>(`/nodes/${id}/templates`),
+
+  /** A month's diary entries: `2026-10`. */
+  diaryDays: (month: string) => request<DiaryEntry[]>(`/diary/days?month=${encodeURIComponent(month)}`),
+
+  /** The entries before and after a diary entry, by date. */
+  diaryAround: (id: number) =>
+    request<{ prev: DiaryEntry | null; next: DiaryEntry | null }>(`/diary/around/${id}`),
+
   /**
    * `base_updated_at`: refused with 409 if the node was saved since then.
    * `restore`: the text is a revision brought back, so what it replaces is
diff --git a/web/src/lib/commands.ts b/web/src/lib/commands.ts
index 6b27180..99a7f76 100644
--- a/web/src/lib/commands.ts
+++ b/web/src/lib/commands.ts
@@ -156,6 +156,23 @@ const spaceNames = () => workspace.spaces.map((space) => space.slug)
 /** The capture tokens' names, for Tab after `:token rm`; null until fetched. */
 let tokenNames: string[] | null = null
 
+/** The templates of the space last asked about, for `:new` to complete. */
+let templateCache: { space: number; names: string[] } | null = null
+
+/** Tab cannot wait for the server: the names come on the press after the first. */
+function templateNames(): string[] {
+  const here = workspace.spaceId
+  if (here === null) return []
+  if (templateCache?.space !== here) {
+    templateCache = { space: here, names: [] }
+    void api.templates(here).then(
+      (templates) => (templateCache = { space: here, names: templates.map((t) => t.slug) }),
+      () => (templateCache = null),
+    )
+  }
+  return templateCache.names
+}
+
 /** `:encrypt` and `:decrypt`: a file, or everything under a folder. */
 const sealTarget = (encrypt: boolean) =>
   workspace.guard(async () => {
@@ -526,23 +543,42 @@ export const commands: CommandSpec[] = [
   {
     name: 'new',
     aliases: ['n', 'o'],
-    args: '[yyyy-mm-dd]',
+    args: '[template] [yyyy-mm-dd] [name]',
     group: 'documents',
-    help: 'start a new document here, optionally dated',
+    help: "start a new document here — from one of the space's templates, dated, named; in the diary from templates/day",
+    complete: (arg) => (arg.includes(' ') ? [] : templateNames()),
     run: async (arg) => {
       await workspace.guard(async () => {
-        await workspace.createDocument()
-        if (arg) {
-          const at = parseDay(arg)
-          if (at === null) return workspace.say(`not a date: ${arg}`, 'error')
-          workspace.draft.created_at = at
-          workspace.dirty = true
-          await workspace.save()
+        const words = arg.trim().split(/\s+/).filter(Boolean)
+        const here = workspace.spaceId
+        const templates = words.length && here !== null ? await api.templates(here) : []
+        if (words.length && here !== null) templateCache = { space: here, names: templates.map((t) => t.slug) }
+        const wanted = words[0]?.toLowerCase()
+        const template = templates.find((t) => t.slug === wanted || t.name.toLowerCase() === wanted)
+        if (template) words.shift()
+        let created_at: number | undefined
+        if (words.length && /^\d{4}-\d{2}-\d{2}$/.test(words[0])) {
+          const at = parseDay(words[0])
+          if (at === null) return workspace.say(`not a date: ${words[0]}`, 'error')
+          created_at = at
+          words.shift()
         }
+        await workspace.createDocument(words.join(' '), { created_at, template_id: template?.id })
       })
       hooks.focusEditor()
     },
   },
+  {
+    name: 'cal',
+    aliases: ['calendar'],
+    group: 'documents',
+    help: 'the diary by month — h/l a day, j/k a week, H/L a month, Enter opens the day or starts it',
+    run: () =>
+      workspace.guard(async () => {
+        if (workspace.overlay === 'calendar') return void (workspace.overlay = 'none')
+        await workspace.openCalendar()
+      }),
+  },
   {
     name: 'agenda',
     aliases: ['ag'],
diff --git a/web/src/lib/store.svelte.ts b/web/src/lib/store.svelte.ts
index 837ac6b..9009dbf 100644
--- a/web/src/lib/store.svelte.ts
+++ b/web/src/lib/store.svelte.ts
@@ -9,6 +9,7 @@ import {
   type Board,
   type Card,
   type Crumb,
+  type DiaryEntry,
   type WorkspaceNode,
   type MediaFile,
   type NodeSummary,
@@ -18,7 +19,7 @@ import {
   type TrashItem,
   type VaultStatus,
 } from './api'
-import { formatBytes, formatStamp, isTouchDevice, sealedNote, type Heading } from './util'
+import { formatBytes, formatDay, formatStamp, isTouchDevice, parseDay, sealedNote, type Heading } from './util'
 
 export type Pane = 'list' | 'document'
 /** The tree of documents, or the board of the space being browsed. */
@@ -282,7 +283,7 @@ class Workspace {
   pane = $state<Pane>('list')
   flash = $state<Flash>(null)
 
-  overlay = $state<'none' | 'help' | 'media' | 'overview' | 'agenda' | 'actions' | 'verify' | 'outline' | 'trash' | 'history' | 'backlinks'>('none')
+  overlay = $state<'none' | 'help' | 'media' | 'overview' | 'agenda' | 'actions' | 'verify' | 'outline' | 'trash' | 'history' | 'backlinks' | 'calendar'>('none')
   /** `gO`: the headings of what is on screen, to jump between from the keyboard. */
   outline = $state.raw<Heading[]>([])
   outlineCursor = $state(0)
@@ -291,9 +292,13 @@ class Workspace {
    * What is due or in hand on every board, kept loaded all the time: the bar
    * counts from it, so what is late is in sight without going to look.
    */
-  agenda = $state<Agenda>({ cards: [], diary_today: null })
+  agenda = $state<Agenda>({ cards: [], diary_today: null, on_this_day: [] })
   agendaCursor = $state(0)
 
+  /** `C`: the day the calendar's cursor is on, `2026-10-20`, and its month's entries. */
+  calendarDay = $state('')
+  calendarEntries = $state.raw<DiaryEntry[]>([])
+
   /** A search across every space rather than the one being browsed — Ctrl-P. */
   globalSearch = $state(false)
 
@@ -939,11 +944,15 @@ class Workspace {
     else await this.openNode(selected.id, edit)
   }
 
-  /** A new document is created immediately so uploads have something to attach to. */
-  async createDocument(name = '') {
+  /**
+   * A new document is created immediately so uploads have something to attach
+   * to. In the diary it starts from `templates/day` when there is one; the
+   * server sees to that, so capture does the same.
+   */
+  async createDocument(name = '', from: { created_at?: number; template_id?: number } = {}) {
     const parent = this.parentId
     if (parent === null) return
-    const node = await api.createNode({ parent_id: parent, name, body: '' })
+    const node = await api.createNode({ parent_id: parent, name, body: '', ...from })
     this.query = ''
     this.globalSearch = false
     await this.refresh()
@@ -1285,7 +1294,7 @@ class Workspace {
     } catch {
       /* the counter is a convenience; a failed refresh leaves the last one up */
     }
-    this.agendaCursor = Math.min(this.agendaCursor, Math.max(this.agendaCards.length - 1, 0))
+    this.agendaCursor = Math.min(this.agendaCursor, Math.max(this.agendaCards.length + this.agenda.on_this_day.length - 1, 0))
   }
 
   /**
@@ -1302,6 +1311,52 @@ class Workspace {
     this.overlay = 'agenda'
   }
 
+  /** `C`: the calendar, on the day of the entry being read or else today. */
+  async openCalendar() {
+    const open = this.open
+    const reading = open && this.spaces.find((space) => space.id === open.path[0]?.id)?.role === 'diary'
+    this.calendarDay = formatDay(reading ? open.created_at : Math.floor(Date.now() / 1000))
+    await this.loadCalendar()
+    this.overlay = 'calendar'
+  }
+
+  async loadCalendar() {
+    this.calendarEntries = await api.diaryDays(this.calendarDay.slice(0, 7))
+  }
+
+  /** The calendar's cursor, `days` along or `months` over; a month keeps the day where it can. */
+  async moveCalendar(days: number, months = 0) {
+    const [y, m, d] = this.calendarDay.split('-').map(Number)
+    const last = new Date(y, m - 1 + months + 1, 0).getDate()
+    const date = new Date(y, m - 1 + months, Math.min(d, last) + days, 12)
+    const before = this.calendarDay.slice(0, 7)
+    this.calendarDay = formatDay(Math.floor(date.getTime() / 1000))
+    if (this.calendarDay.slice(0, 7) !== before) await this.loadCalendar()
+  }
+
+  /** Enter in the calendar: that day's entry, or a new one dated that day. */
+  async openCalendarDay() {
+    const day = this.calendarDay
+    const entry = this.calendarEntries.find((e) => e.day === day)
+    this.overlay = 'none'
+    if (entry) return this.openPath(entry.path)
+    const home = this.spaces.find((space) => space.role === 'diary')
+    if (!home) return this.say('there is no diary to write in', 'error')
+    if (this.parentId !== home.id) await this.enterSpace(home.id)
+    await this.createDocument('', { created_at: parseDay(day) ?? undefined })
+  }
+
+  /** `[d` / `]d`: the diary entry before or after the one being read. */
+  async stepEntry(by: -1 | 1) {
+    const open = this.open
+    if (!open) return this.say('nothing open', 'error')
+    const { prev, next } = await api.diaryAround(open.id)
+    const entry = by < 0 ? prev : next
+    if (!entry) return this.say(by < 0 ? 'no entry before this one' : 'no entry after this one')
+    await this.openPath(entry.path)
+    this.say(entry.day)
+  }
+
   /** Enter in the agenda: to the card, on its own board. */
   async goToCard(card: AgendaCard) {
     this.overlay = 'none'