diff --git a/diigo-cache/src/query.ts b/diigo-cache/src/query.ts
new file mode 100644
index 0000000..596cb1c
--- /dev/null
+++ b/diigo-cache/src/query.ts
@@ -0,0 +1,107 @@
+/**
+ * @file the public page's filters — goal 1d, **not yet implemented**: the
+ * design is pinned by the skipped suites in tests/query.test.ts and
+ * tests/caches.test.ts ("public page filters").
+ *
+ * One filter, two spellings: devs pass a {@link FilterSpec} object
+ * (`{ days: 7, q: "#weekly" }`); URLs carry the same fields as params
+ * (`?days=7&q=%23weekly`, empty fields = absent). `q` also takes the
+ * search operators large audiences already know — gmail's `after:`,
+ * `before:`, `newer_than:7d`; Slack's `during:` (alias `in:`); GitHub's
+ * `created:`/`updated:` — plus words, `"phrases"`, `#tag`/`tag:tag`, and
+ * `-` negation.
+ *
+ * Time is UTC (Z) throughout; weeks are ISO 8601 (Monday first, so a
+ * weekend stays together). Every window is half-open: `after` inclusive
+ * from 00:00Z, `before` exclusive at 00:00Z — so GitHub's inclusive
+ * `a..b` ranges are deliberately not offered.
+ *
+ * Applied while walking diigo's pages (updated-desc). `by=updated` finds
+ * an old window by binary search over the sorted pages; `by=created`
+ * walks from page 1 (an old bookmark edited lately sits near page 1).
+ * Either way a request spends at most {@link FETCH_BUDGET} diigo fetches
+ * (cached pages are free) and says so when results are incomplete.
+ *
+ * @see https://mailmeteor.com/blog/search-gmail-by-date
+ * @see https://slack.com/help/articles/202528808
+ * @see https://docs.github.com/en/search-github/searching-on-github/searching-for-repositories
+ */
+
+import type { Item } from "./items.js";
+
+/**
+ * diigo fetches one request may spend (cache hits are free); under the
+ * Workers free plan's 50 external subrequests per invocation
+ *
+ * @see https://developers.cloudflare.com/workers/platform/limits/
+ */
+export const FETCH_BUDGET = 40;
+
+/**
+ * a filter as devs write it; URL params map onto these fields one-to-one
+ * (strings, with "" meaning absent). Dates are `yyyy-mm-dd` (gmail's
+ * `yyyy/mm/dd` too); periods are `2025`, `2025-03`, `2025-Q1`, or ISO week
+ * `2025-W01`.
+ */
+export type FilterSpec = {
+	/** the last N days, counted back from now (1–3650) */
+	days?: number | string;
+	/** inclusive lower bound, from 00:00Z */
+	after?: string;
+	/** exclusive upper bound, at 00:00Z */
+	before?: string;
+	/** a named period: shorthand for its after/before pair */
+	in?: string;
+	/** which date the window, the listed date, and the sort use */
+	by?: "updated" | "created" | "";
+	/** words, phrases, tags, and operators */
+	q?: string;
+};
+
+/** one search term; `negated` for a leading `-` */
+export type Term = { text: string; negated: boolean };
+
+/** a parsed filter; an empty one (no window, no terms) filters nothing */
+export type Query = {
+	/** which date the window, the listed date, and the sort use (default
+	 * `updated`, diigo's own order) */
+	by: "updated" | "created";
+	/** inclusive lower bound */
+	after?: Date;
+	/** exclusive upper bound */
+	before?: Date;
+	/** words and phrases: each must appear in title, description, or url */
+	words: Term[];
+	/** tags: exact, case-insensitive match against the item's tags */
+	tags: Term[];
+};
+
+/** a refused filter: the message is safe to show and log */
+export type QueryError = { error: string };
+
+/**
+ * resolve a filter: fields and `q` operators combine; a bound given twice
+ * (by fields, operators, or both) is refused, as is an empty window.
+ *
+ * @param now the clock `days`/`newer_than` count back from (passed in,
+ * not read ambiently, so tests pin it)
+ */
+export function toQuery(spec: FilterSpec, now: Date): Query | QueryError {
+	void spec;
+	void now;
+	throw new Error("toQuery: not implemented (goal 1d)");
+}
+
+/** {@link toQuery} over the public page's URL params */
+export function parseQuery(params: URLSearchParams, now: Date): Query | QueryError {
+	void params;
+	void now;
+	throw new Error("parseQuery: not implemented (goal 1d)");
+}
+
+/** does `item` fall in the window and satisfy every term? */
+export function matches(item: Item, query: Query): boolean {
+	void item;
+	void query;
+	throw new Error("matches: not implemented (goal 1d)");
+}
diff --git a/diigo-cache/tests/caches.test.ts b/diigo-cache/tests/caches.test.ts
index b406de6..fe01bf7 100644
--- a/diigo-cache/tests/caches.test.ts
+++ b/diigo-cache/tests/caches.test.ts
@@ -3,6 +3,7 @@ import { runInDurableObject } from "cloudflare:test";
 import { describe, expect, it, vi } from "vitest";
 import worker from "../src/index.js";
 import { toWebkey } from "../src/webkeys.js";
+import { FETCH_BUDGET } from "../src/query.js";
 
 // matches tests/fake-webapp.js: 30 items, every third private
 const WEBAPP_ID = "fake-webapp-id";
@@ -139,3 +140,155 @@ describe("worker routes", () => {
 		expect(res.status).toBe(404);
 	});
 });
+
+/** `yyyy-Www` for the ISO 8601 week holding `d` (UTC) */
+function isoWeek(d: Date): string {
+	const t = new Date(Date.UTC(d.getUTCFullYear(), d.getUTCMonth(), d.getUTCDate()));
+	const day = t.getUTCDay() || 7;
+	t.setUTCDate(t.getUTCDate() + 4 - day); // the week's Thursday names its year
+	const year = t.getUTCFullYear();
+	const week = Math.ceil(((t.getTime() - Date.UTC(year, 0, 1)) / 86400000 + 1) / 7);
+	return `${year}-W${String(week).padStart(2, "0")}`;
+}
+
+describe.skip("public page filters (goal 1d)", () => {
+	// the fake's dated account: "dated n" updated n-1 days + 1h ago;
+	// #weekly on every 7th; every 10th private; every 5th created 100
+	// days before it was updated
+	const call = (path: string, init?: RequestInit) =>
+		worker.fetch(new Request(`https://diigo-cache.test${path}`, init), env as never);
+	const wireDated = async () => {
+		const res = await call("/_wire", {
+			method: "POST",
+			headers: { "content-type": "application/json" },
+			body: JSON.stringify({ webappId: "fake-dated-webapp", mode: "public" }),
+		});
+		expect(res.status).toBe(200);
+		return "/public/dated_dan";
+	};
+	const titlesIn = (html: string) => [...html.matchAll(/>(dated \d+)<\/a>/g)].map((m) => m[1]);
+	const dated = (...ns: number[]) => ns.map((n) => `dated ${n}`);
+
+	it("?days=7 lists the last week, walking only the diigo pages it needs", async () => {
+		const page = await wireDated();
+		const before = await testEnv.WEBAPP.calls();
+		const html = await (await call(`${page}?days=7`)).text();
+		expect(titlesIn(html)).toEqual(dated(1, 2, 3, 4, 5, 6, 7));
+		expect((await testEnv.WEBAPP.calls()) - before).toBeLessThanOrEqual(1);
+	});
+
+	it("?by=created windows, lists, and dates by when it was bookmarked", async () => {
+		const page = await wireDated();
+		const html = await (await call(`${page}?days=7&by=created`)).text();
+		// 5 was updated this week but bookmarked 100 days earlier
+		expect(titlesIn(html)).toEqual(dated(1, 2, 3, 4, 6, 7));
+		const updated = await (await call(`${page}?days=7`)).text();
+		expect(titlesIn(updated)).toContain("dated 5");
+	});
+
+	it("?by=created over a longer window sorts by created, newest first", async () => {
+		const page = await wireDated();
+		const html = await (await call(`${page}?days=150&by=created&q=${encodeURIComponent("#weekly")}`)).text();
+		// weekly: 7,14,21,28,35,42,49,56; 35 was created ~134 days ago
+		// (100 days before its update), so it sorts after 56 (~55 days)
+		expect(titlesIn(html)).toEqual(dated(7, 14, 21, 28, 42, 49, 56, 35));
+	});
+
+	it("?days=30 pages the matches 24 at a time; links keep the filter", async () => {
+		const page = await wireDated();
+		const first = await (await call(`${page}?days=30`)).text();
+		const want = Array.from({ length: 30 }, (_, k) => k + 1).filter((n) => n % 10 !== 0);
+		expect(titlesIn(first)).toEqual(dated(...want.slice(0, 24)));
+		expect(first).toContain(`href="${page}?days=30&amp;page=2"`);
+		const second = await (await call(`${page}?days=30&page=2`)).text();
+		expect(titlesIn(second)).toEqual(dated(...want.slice(24)));
+	});
+
+	it("?after=&before= selects a date range", async () => {
+		const page = await wireDated();
+		const day = (n: number) => new Date(Date.now() - (n - 1) * 24 * 60 * 60 * 1000 - 60 * 60 * 1000).toISOString().slice(0, 10);
+		// items are 24h apart, so each has its own UTC day: from dated 12's
+		// day (inclusive) up to dated 9's day (exclusive); 10 is private
+		const html = await (await call(`${page}?after=${day(12)}&before=${day(9)}`)).text();
+		expect(titlesIn(html)).toEqual(dated(11, 12));
+	});
+
+	it("?q=#weekly&days=60 filters by tag; private items stay out", async () => {
+		const page = await wireDated();
+		const html = await (await call(`${page}?days=60&q=${encodeURIComponent("#weekly")}`)).text();
+		expect(titlesIn(html)).toEqual(dated(7, 14, 21, 28, 35, 42, 49, 56));
+	});
+
+	it("?q= alone searches all time", async () => {
+		const page = await wireDated();
+		const html = await (await call(`${page}?q=fragments`)).text();
+		expect(titlesIn(html)).toEqual(dated(7, 14, 21, 28, 35, 42, 49, 56));
+	});
+
+	it("a request spends at most FETCH_BUDGET diigo fetches; incomplete results say so, and a reload continues", async () => {
+		const res = await call("/_wire", {
+			method: "POST",
+			headers: { "content-type": "application/json" },
+			body: JSON.stringify({ webappId: "fake-deep-webapp", mode: "public" }),
+		});
+		expect(res.status).toBe(200);
+		// deep_dee: 50 diigo pages; a search matching nothing must walk them all
+		const before = await testEnv.WEBAPP.calls();
+		const first = await call("/public/deep_dee?q=nomatch", { headers: { accept: "application/json" } });
+		expect(await first.json()).toMatchObject({ complete: false, items: [] });
+		expect((await testEnv.WEBAPP.calls()) - before).toBeLessThanOrEqual(FETCH_BUDGET + 1);
+		const html = await (await call("/public/deep_dee?q=nomatch")).text();
+		expect(html).toMatch(/complete|no matches/);
+		const again = await call("/public/deep_dee?q=nomatch", { headers: { accept: "application/json" } });
+		expect(await again.json()).toMatchObject({ complete: true, items: [] });
+	});
+
+	it("JSON answers carry the canonical filter, so devs see what was understood", async () => {
+		const page = await wireDated();
+		const res = await call(`${page}?days=7&q=${encodeURIComponent("#Weekly")}`, { headers: { accept: "application/json" } });
+		expect(await res.json()).toMatchObject({
+			filter: { by: "updated", tags: [{ text: "weekly", negated: false }] },
+			complete: true,
+		});
+	});
+
+	it("?in= an old week costs O(log pages) diigo fetches with by=updated, not a walk from page 1", async () => {
+		const res = await call("/_wire", {
+			method: "POST",
+			headers: { "content-type": "application/json" },
+			body: JSON.stringify({ webappId: "fake-deep-webapp", mode: "public" }),
+		});
+		expect(res.status).toBe(200);
+		// deep_dee: 1200 bookmarks, one a day, 50 diigo pages; a week ~2.5
+		// years back sits near page 38 — a walk from page 1 would cost ~38
+		const twoAndAHalfYearsAgo = new Date(Date.now() - 900 * 24 * 60 * 60 * 1000);
+		const week = isoWeek(twoAndAHalfYearsAgo);
+		const before = await testEnv.WEBAPP.calls();
+		const html = await (await call(`/public/deep_dee?in=${week}`)).text();
+		// one a day; every 10th is private
+		expect(titlesIn(html).length).toBeGreaterThanOrEqual(6);
+		expect(titlesIn(html).length).toBeLessThanOrEqual(7);
+		expect((await testEnv.WEBAPP.calls()) - before).toBeLessThanOrEqual(12);
+	});
+
+	it("a malformed filter is a 400 with a message, not an empty list", async () => {
+		const page = await wireDated();
+		const res = await call(`${page}?days=7x`);
+		expect(res.status).toBe(400);
+		expect(await res.text()).toMatch(/days/);
+	});
+
+	it("the form offers the day presets, date inputs, and search, echoing the current filter", async () => {
+		const page = await wireDated();
+		const html = await (await call(`${page}?days=30&q=ocap`)).text();
+		expect(html).toMatch(/<select name="days">/);
+		expect(html).toMatch(/<select name="by">/);
+		for (const n of [7, 30, 90, 365]) expect(html).toContain(`<option value="${n}"`);
+		expect(html).toContain('<option value="30" selected>');
+		expect(html).toMatch(/<input type="date" name="after"/);
+		expect(html).toMatch(/<input type="date" name="before"/);
+		expect(html).toMatch(/<input[^>]* name="q"[^>]* value="ocap"/);
+		// times are UTC, and the page says so
+		expect(html).toMatch(/UTC/);
+	});
+});
diff --git a/diigo-cache/tests/fake-webapp.js b/diigo-cache/tests/fake-webapp.js
index bab8c96..0705874 100644
--- a/diigo-cache/tests/fake-webapp.js
+++ b/diigo-cache/tests/fake-webapp.js
@@ -10,6 +10,32 @@ import { RpcTarget, WorkerEntrypoint } from "cloudflare:workers";
 const KNOWN_WEBAPP = "fake-webapp-id";
 const TOTAL = 30;
 
+/** a second account, for date filters (goal 1d): 60 bookmarks, item n
+ * updated n-1 days + 1 hour before the call, in diigo's updated-desc
+ * order; tagged ocap, plus weekly every 7th; every 10th private; every
+ * 5th an old bookmark edited recently (created 100 days before updated) */
+const DATED_WEBAPP = "fake-dated-webapp";
+const DATED_TOTAL = 60;
+/** the same shape, 1200 deep (~3.3 years, 50 pages): for walk cost */
+const DEEP_WEBAPP = "fake-deep-webapp";
+const DEEP_TOTAL = 1200;
+const HOUR = 60 * 60 * 1000;
+
+function datedItem(n, now, user = "dated_dan") {
+	return {
+		link_id: 5000 + n,
+		url: `https://dated.example/${n}`,
+		title: `dated ${n}`,
+		description: n % 7 === 0 ? "a week of fragments" : "",
+		private: n % 10 === 0,
+		u_name: user,
+		user_id: 777,
+		tags: n % 7 === 0 ? "ocap,weekly" : "ocap",
+		created_at: Math.floor((now - (n - 1) * 24 * HOUR - HOUR - (n % 5 === 0 ? 100 * 24 * HOUR : 0)) / 1000),
+		updated_at: Math.floor((now - (n - 1) * 24 * HOUR - HOUR) / 1000),
+	};
+}
+
 /** item n (1-based, in diigo's order): diigo's field names, made-up
  * values. link_id and updated_at are scrambled (distinct; 7 and 11 are
  * coprime to 31), so neither column sorts back into diigo's order — a
@@ -35,32 +61,40 @@ let calls = 0;
 class FakeGet extends RpcTarget {
 	#path;
 	#params;
-	constructor(path, params) {
+	/** null (the plain account), "dated", or "deep" */
+	#dated;
+	constructor(path, params, dated) {
 		super();
 		this.#path = path;
 		this.#params = params;
+		this.#dated = dated;
 	}
 	pathjoin(ref) {
-		return new FakeGet(ref, this.#params);
+		return new FakeGet(ref, this.#params, this.#dated);
 	}
 	query(params) {
-		return new FakeGet(this.#path, { ...this.#params, ...params });
+		return new FakeGet(this.#path, { ...this.#params, ...params }, this.#dated);
 	}
 	async get() {
 		calls += 1;
 		if (this.#path !== "load_user_items") throw new Error(`fake webapp: no route ${this.#path}`);
 		const count = Number(this.#params.count);
 		const page = Number(this.#params.page_num);
+		const total = this.#dated === "deep" ? DEEP_TOTAL : this.#dated ? DATED_TOTAL : TOTAL;
+		const now = Date.now();
 		const items = [];
-		for (let n = (page - 1) * count + 1; n <= Math.min(page * count, TOTAL); n += 1) items.push(item(n));
-		return JSON.stringify({ total: TOTAL, items });
+		for (let n = (page - 1) * count + 1; n <= Math.min(page * count, total); n += 1) {
+			items.push(this.#dated ? datedItem(n, now, this.#dated === "deep" ? "deep_dee" : "dated_dan") : item(n));
+		}
+		return JSON.stringify({ total, items });
 	}
 }
 
 export class WebAppFactory extends WorkerEntrypoint {
 	async at(id) {
-		if (id !== KNOWN_WEBAPP) throw new Error("fake webapp: unknown id");
-		return new FakeGet("", {});
+		const kind = { [KNOWN_WEBAPP]: null, [DATED_WEBAPP]: "dated", [DEEP_WEBAPP]: "deep" }[id];
+		if (kind === undefined) throw new Error("fake webapp: unknown id");
+		return new FakeGet("", {}, kind);
 	}
 	/** how many diigo calls so far (test hook) */
 	async calls() {
diff --git a/diigo-cache/tests/query.test.ts b/diigo-cache/tests/query.test.ts
new file mode 100644
index 0000000..886627e
--- /dev/null
+++ b/diigo-cache/tests/query.test.ts
@@ -0,0 +1,206 @@
+import { describe, expect, it } from "vitest";
+import { matches, parseQuery, toQuery } from "../src/query.js";
+import type { FilterSpec, Query, QueryError } from "../src/query.js";
+
+// goal 1d (capsite checklist): the design as tests; unskip as it lands
+
+const NOW = new Date("2026-10-07T12:00:00.000Z");
+const DAY = 24 * 60 * 60 * 1000;
+
+const fromUrl = (qs: string) => parseQuery(new URLSearchParams(qs), NOW);
+const ok = (q: Query | QueryError) => {
+	if ("error" in q) throw new Error(`expected a query: ${q.error}`);
+	return q;
+};
+const url = (qs: string) => ok(fromUrl(qs));
+const spec = (s: FilterSpec) => ok(toQuery(s, NOW));
+const refused = (q: Query | QueryError) => {
+	expect(q).toHaveProperty("error");
+	return (q as QueryError).error;
+};
+const day = (iso: string) => new Date(`${iso}T00:00:00.000Z`);
+const range = (q: Query) => [q.after?.toISOString().slice(0, 10), q.before?.toISOString().slice(0, 10)];
+
+describe.skip("filters: one spec, two spellings (goal 1d)", () => {
+	it("devs write { days: 7 }; URLs write ?days=7; same query", () => {
+		expect(spec({ days: 7 })).toEqual(url("days=7"));
+		expect(spec({ days: 7 }).after).toEqual(new Date(NOW.getTime() - 7 * DAY));
+	});
+
+	it("an empty spec or URL filters nothing", () => {
+		expect(spec({})).toEqual({ by: "updated", words: [], tags: [] });
+		expect(url("")).toEqual({ by: "updated", words: [], tags: [] });
+	});
+
+	it("empty URL fields mean absent (a GET form submits them all)", () => {
+		expect(url("days=7&after=&before=&in=&by=&q=")).toEqual(url("days=7"));
+	});
+
+	it("refuses a days value that isn't a whole number from 1 to 3650", () => {
+		for (const bad of ["0", "-7", "7x", "1.5", "3651"]) expect(refused(fromUrl(`days=${bad}`))).toMatch(/days/);
+		expect(refused(toQuery({ days: 0 }, NOW))).toMatch(/days/);
+	});
+});
+
+describe.skip("windows: UTC, half-open (goal 1d)", () => {
+	it("after/before are UTC days: after inclusive from 00:00Z, before exclusive", () => {
+		expect(range(url("after=2026-01-01&before=2026-02-01"))).toEqual(["2026-01-01", "2026-02-01"]);
+		expect(url("after=2026/01/01").after).toEqual(day("2026-01-01"));
+	});
+
+	it("in= names a year, month, quarter, or ISO week", () => {
+		expect(range(url("in=2025"))).toEqual(["2025-01-01", "2026-01-01"]);
+		expect(range(url("in=2025-03"))).toEqual(["2025-03-01", "2025-04-01"]);
+		expect(range(url("in=2025-12"))).toEqual(["2025-12-01", "2026-01-01"]);
+		expect(range(url("in=2025-Q1"))).toEqual(["2025-01-01", "2025-04-01"]);
+		expect(range(url("in=2025-Q4"))).toEqual(["2025-10-01", "2026-01-01"]);
+		// ISO 8601: weeks start Monday; week 1 holds the year's first Thursday
+		expect(range(url("in=2025-W01"))).toEqual(["2024-12-30", "2025-01-06"]);
+		expect(range(url("in=2026-W53"))).toEqual(["2026-12-28", "2027-01-04"]);
+	});
+
+	it("refuses malformed dates and periods", () => {
+		expect(refused(fromUrl("after=2026-13-01"))).toMatch(/after/);
+		expect(refused(fromUrl("before=yesterday"))).toMatch(/before/);
+		// 2025 has 52 ISO weeks (it starts on a Wednesday, not a leap year)
+		for (const bad of ["2025-13", "2025-Q5", "2025-W53", "2025-W00", "25", "2025-1"]) {
+			expect(refused(fromUrl(`in=${bad}`))).toMatch(/in/);
+		}
+	});
+
+	it("refuses a bound given twice, and an empty window", () => {
+		expect(refused(fromUrl("days=7&after=2026-01-01"))).toMatch(/days.*after|after.*days/);
+		expect(refused(fromUrl("in=2025&days=7"))).toMatch(/in/);
+		expect(refused(fromUrl("in=2025&before=2025-02-01"))).toMatch(/in/);
+		expect(refused(fromUrl("after=2026-02-01&before=2026-02-01"))).toMatch(/after.*before|before.*after/);
+	});
+
+	it("days combines with before", () => {
+		const q = url("days=30&before=2026-10-01");
+		expect(q.after).toEqual(new Date(NOW.getTime() - 30 * DAY));
+		expect(q.before).toEqual(day("2026-10-01"));
+	});
+
+	it("by=created or by=updated picks the date (default updated); anything else is refused", () => {
+		expect(url("days=7").by).toBe("updated");
+		expect(url("days=7&by=created").by).toBe("created");
+		expect(refused(fromUrl("days=7&by=modified"))).toMatch(/by/);
+	});
+});
+
+describe.skip("q: terms and operators (goal 1d)", () => {
+	const q = (text: string) => url(`q=${encodeURIComponent(text)}`);
+
+	it("words, phrases, #tags, tag:, and - negation; case-insensitive", () => {
+		const parsed = q('Foo bar -baz "exact phrase" #Weekly tag:ocap -#draft -tag:old');
+		expect(parsed.words).toEqual([
+			{ text: "foo", negated: false },
+			{ text: "bar", negated: false },
+			{ text: "baz", negated: true },
+			{ text: "exact phrase", negated: false },
+		]);
+		expect(parsed.tags).toEqual([
+			{ text: "weekly", negated: false },
+			{ text: "ocap", negated: false },
+			{ text: "draft", negated: true },
+			{ text: "old", negated: true },
+		]);
+	});
+
+	it("gmail's after:/before:/newer_than: set the window", () => {
+		expect(range(q("after:2026-01-01 before:2026/02/01"))).toEqual(["2026-01-01", "2026-02-01"]);
+		expect(q("newer_than:7d").after).toEqual(new Date(NOW.getTime() - 7 * DAY));
+		expect(q("newer_than:2w").after).toEqual(new Date(NOW.getTime() - 14 * DAY));
+		// months and years are calendar steps back, in UTC
+		expect(q("newer_than:1m").after).toEqual(new Date("2026-09-07T12:00:00.000Z"));
+		expect(q("newer_than:1y").after).toEqual(new Date("2025-10-07T12:00:00.000Z"));
+	});
+
+	it("Slack's during: (alias in:) names a period", () => {
+		expect(range(q("during:2025-Q1"))).toEqual(["2025-01-01", "2025-04-01"]);
+		expect(range(q("in:2025-W01"))).toEqual(["2024-12-30", "2025-01-06"]);
+	});
+
+	it("GitHub-style created:/updated: name the date and the period at once", () => {
+		const c = q("created:2025");
+		expect(c.by).toBe("created");
+		expect(range(c)).toEqual(["2025-01-01", "2026-01-01"]);
+		expect(q("updated:2025-W03").by).toBe("updated");
+	});
+
+	it("operators and fields combine, but a bound given twice is refused", () => {
+		const both = url(`by=created&q=${encodeURIComponent("during:2025 #weekly")}`);
+		expect(both.by).toBe("created");
+		expect(both.tags).toEqual([{ text: "weekly", negated: false }]);
+		expect(refused(fromUrl(`days=7&q=${encodeURIComponent("newer_than:30d")}`))).toMatch(/newer_than|days/);
+		expect(refused(fromUrl(`by=updated&q=${encodeURIComponent("created:2025")}`))).toMatch(/by|created/);
+	});
+
+	it("an unknown word:stuff is plain text (so urls work as words)", () => {
+		expect(q("https://erights.org foo:bar").words).toEqual([
+			{ text: "https://erights.org", negated: false },
+			{ text: "foo:bar", negated: false },
+		]);
+	});
+
+	it("a malformed known operator is refused, not searched as text", () => {
+		expect(refused(fromUrl(`q=${encodeURIComponent("newer_than:7x")}`))).toMatch(/newer_than/);
+		expect(refused(fromUrl(`q=${encodeURIComponent("during:2025-Q5")}`))).toMatch(/during/);
+	});
+});
+
+/** an item updated at `iso`, diigo-shaped */
+const item = (iso: string, extra: Record<string, unknown> = {}) => ({
+	updated_at: new Date(iso).getTime() / 1000,
+	title: "",
+	description: "",
+	url: "https://example.com/",
+	tags: "",
+	...extra,
+});
+const query = (q: Partial<Query>): Query => ({ by: "updated", words: [], tags: [], ...q });
+
+describe.skip("matches (goal 1d)", () => {
+	it("the window is half-open: after inclusive, before exclusive", () => {
+		const q = query({ after: day("2026-01-01"), before: day("2026-02-01") });
+		expect(matches(item("2026-01-01T00:00:00.000Z"), q)).toBe(true);
+		expect(matches(item("2025-12-31T23:59:59.000Z"), q)).toBe(false);
+		expect(matches(item("2026-01-31T23:59:59.000Z"), q)).toBe(true);
+		expect(matches(item("2026-02-01T00:00:00.000Z"), q)).toBe(false);
+	});
+
+	it("by=created windows on created_at instead of updated_at", () => {
+		const jan = { after: day("2026-01-01") };
+		// an old bookmark, edited recently
+		const edited = item("2026-01-05T00:00:00Z", { created_at: new Date("2025-06-01T00:00:00Z").getTime() / 1000 });
+		expect(matches(edited, query({ ...jan, by: "updated" }))).toBe(true);
+		expect(matches(edited, query({ ...jan, by: "created" }))).toBe(false);
+	});
+
+	it("every word must appear in the title, description, or url (case-insensitive)", () => {
+		const it1 = item("2026-01-05T00:00:00Z", { title: "Capability Patterns", url: "https://erights.org/x" });
+		expect(matches(it1, query({ words: [{ text: "capability", negated: false }] }))).toBe(true);
+		expect(matches(it1, query({ words: [{ text: "erights", negated: false }] }))).toBe(true);
+		expect(
+			matches(it1, query({ words: [{ text: "capability", negated: false }, { text: "missing", negated: false }] })),
+		).toBe(false);
+	});
+
+	it("a negated word excludes", () => {
+		const it1 = item("2026-01-05T00:00:00Z", { title: "Capability Patterns" });
+		expect(matches(it1, query({ words: [{ text: "patterns", negated: true }] }))).toBe(false);
+	});
+
+	it("a phrase matches only contiguously", () => {
+		const it1 = item("2026-01-05T00:00:00Z", { description: "object capability patterns" });
+		expect(matches(it1, query({ words: [{ text: "capability patterns", negated: false }] }))).toBe(true);
+		expect(matches(it1, query({ words: [{ text: "patterns object", negated: false }] }))).toBe(false);
+	});
+
+	it("a tag matches a whole comma-separated tag, case-insensitive; not a substring", () => {
+		const it1 = item("2026-01-05T00:00:00Z", { tags: "ocap,Weekly-Notes,js" });
+		expect(matches(it1, query({ tags: [{ text: "weekly-notes", negated: false }] }))).toBe(true);
+		expect(matches(it1, query({ tags: [{ text: "weekly", negated: false }] }))).toBe(false);
+		expect(matches(it1, query({ tags: [{ text: "js", negated: true }] }))).toBe(false);
+	});
+});