diff --git a/diigo-cache/src/index.ts b/diigo-cache/src/index.ts
index ea09df1..224da4d 100644
--- a/diigo-cache/src/index.ts
+++ b/diigo-cache/src/index.ts
@@ -15,7 +15,7 @@
 import { WorkerEntrypoint } from "cloudflare:workers";
 import { DiigoCache, PublicCache } from "./cache.js";
 import type { Item } from "./cache.js";
-import { usernameOf } from "./items.js";
+import { updatedISO, usernameOf } from "./items.js";
 import { toWebkey, idFromWebkey, isWebkey, shashKey } from "./webkeys.js";
 import { pmSave } from "./pm-save.js";
 
@@ -457,7 +457,9 @@ ${items
 		const title = typeof it.title === "string" && it.title ? it.title : url;
 		const desc = typeof it.description === "string" && it.description ? `<br><small>${esc(it.description)}</small>` : "";
 		const href = /^https?:\/\//i.test(url) ? url : "#";
-		return `<li><a href="${esc(href)}">${esc(title)}</a>${desc}</li>`;
+		const when = updatedISO(it);
+		const date = when ? `<time datetime="${when}">${when}</time>` : "(no date)";
+		return `<li>${date} <a href="${esc(href)}">${esc(title)}</a>${desc}</li>`;
 	})
 	.join("\n")}
 </ol>`;
diff --git a/diigo-cache/src/items.ts b/diigo-cache/src/items.ts
index c78cdcc..10dac1f 100644
--- a/diigo-cache/src/items.ts
+++ b/diigo-cache/src/items.ts
@@ -64,3 +64,11 @@ export function usernameOf(item: Item | undefined): string {
 export function publicOnly(rows: ItemRow[]): ItemRow[] {
 	return rows.filter((r) => !r.private);
 }
+
+/** when diigo last updated the item, as `Date#toISOString()`, or "" when
+ * it carries no usable `updated_at` (diigo sends epoch *seconds*) */
+export function updatedISO(item: Item): string {
+	const secs = item.updated_at;
+	if (typeof secs !== "number" || !Number.isFinite(secs)) return "";
+	return new Date(secs * 1000).toISOString();
+}
diff --git a/diigo-cache/tests/caches.test.ts b/diigo-cache/tests/caches.test.ts
index 55523d0..b406de6 100644
--- a/diigo-cache/tests/caches.test.ts
+++ b/diigo-cache/tests/caches.test.ts
@@ -117,6 +117,8 @@ describe("worker routes", () => {
 		const again = await (await call(`/public/${username}?page=2`)).text();
 		expect(again).toContain("<strong>cache: HIT");
 		expect(html).toContain("bookmark 25");
+		// the date comes first, in toISOString() form
+		expect(html).toMatch(/<li><time datetime="\d{4}-\d\d-\d\dT[\d:.]+Z">[^<]+<\/time> <a /);
 		expect(html).not.toContain("bookmark 27"); // private (27 % 3 === 0)
 
 		const json = (await (
diff --git a/diigo-cache/tests/items.test.ts b/diigo-cache/tests/items.test.ts
index 8ebc2db..e3c4326 100644
--- a/diigo-cache/tests/items.test.ts
+++ b/diigo-cache/tests/items.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { publicOnly, toRows, usernameOf } from "../src/items.js";
+import { publicOnly, toRows, updatedISO, usernameOf } from "../src/items.js";
 import type { Item } from "../src/items.js";
 
 /** a load_user_items row: diigo's actual field names (observed
@@ -70,3 +70,14 @@ describe("publicOnly", () => {
 		expect(JSON.stringify(rows)).not.toContain("secret.example");
 	});
 });
+
+describe("updatedISO", () => {
+	it("reads diigo's updated_at as epoch seconds", () => {
+		expect(updatedISO({ updated_at: 1700000000 })).toBe("2023-11-14T22:13:20.000Z");
+	});
+
+	it("answers empty when there is no usable date", () => {
+		expect(updatedISO({})).toBe("");
+		expect(updatedISO({ updated_at: "yesterday" })).toBe("");
+	});
+});