diff --git a/apps/web/src/components/chat/MessagesTimeline.test.tsx b/apps/web/src/components/chat/MessagesTimeline.test.tsx
index 0987b852e716b6db2581e1b06c9b6d608cb87cab..3bf5f482948dd9f31fe9bb3e5486c92373e792ef 100644
--- a/apps/web/src/components/chat/MessagesTimeline.test.tsx
+++ b/apps/web/src/components/chat/MessagesTimeline.test.tsx
@@ -9,7 +9,7 @@ import {
 import { act, createRef, useLayoutEffect, type ReactNode, type Ref } from "react";
 import { renderToStaticMarkup } from "react-dom/server";
 import { create, type ReactTestRenderer } from "react-test-renderer";
-import { beforeAll, describe, expect, it, vi } from "vite-plus/test";
+import { beforeAll, beforeEach, describe, expect, it, vi } from "vite-plus/test";
 import type { LegendListRef, MaintainScrollAtEndOptions } from "@legendapp/list/react";
 import { shouldUseRestingComposerLayout } from "../composerFooterLayout";
 import { useComposerFocusState } from "./useComposerFocusState";
@@ -146,7 +146,9 @@ function matchMedia() {
 let MessagesTimeline: typeof import("./MessagesTimeline").MessagesTimeline;
 let resolvePreviewAnnotationImage: typeof import("./MessagesTimeline").resolvePreviewAnnotationImage;
 
-beforeAll(async () => {
+const ElementStub = class ElementStub {};
+
+function stubDomGlobals() {
   const classList = {
     add: () => {},
     remove: () => {},
@@ -154,6 +156,7 @@ beforeAll(async () => {
     contains: () => false,
   };
 
+  vi.stubGlobal("Element", ElementStub);
   vi.stubGlobal("localStorage", {
     getItem: () => null,
     setItem: () => {},
@@ -161,6 +164,7 @@ beforeAll(async () => {
     clear: () => {},
   });
   vi.stubGlobal("window", {
+    Element: ElementStub,
     matchMedia,
     addEventListener: () => {},
     removeEventListener: () => {},
@@ -177,10 +181,17 @@ beforeAll(async () => {
       offsetHeight: 0,
     },
   });
+}
 
+beforeAll(async () => {
+  stubDomGlobals();
   ({ MessagesTimeline, resolvePreviewAnnotationImage } = await import("./MessagesTimeline"));
 }, 30_000);
 
+// The scroll-settling test clears every global stub; mounted timeline rows
+// still touch `window` through the tooltip's focus handling.
+beforeEach(stubDomGlobals);
+
 const ACTIVE_THREAD_ENVIRONMENT_ID = EnvironmentId.make("environment-local");
 const MESSAGE_CREATED_AT = "2026-03-17T19:12:28.000Z";
 
diff --git a/apps/web/src/components/chat/MessagesTimeline.tsx b/apps/web/src/components/chat/MessagesTimeline.tsx
index 09aa61bd5186fe1589e5a8addb1d0075c1b980f1..976f261981e3082f27ffef7fb5ef07364aa7bc1c 100644
--- a/apps/web/src/components/chat/MessagesTimeline.tsx
+++ b/apps/web/src/components/chat/MessagesTimeline.tsx
@@ -2063,12 +2063,49 @@ function RevertUserMessageButton({
   );
 }
 
+/**
+ * Hover-revealed wall-clock time with a full-date tooltip — the same metadata
+ * presentation as message rows, for work entries and turn folds. The parent
+ * carries `group/timeline-row`; hover or focus on an existing control reveals
+ * the time without adding a tab stop. Hidden timestamps stay outside the row
+ * layout. Visibility changes immediately so leaving flow cannot overlap text
+ * during a fade-out. Render it as the row's rightmost flex child so the
+ * revealed time lands at the right edge, clear of disclosure controls.
+ */
+function TimelineRowTimestamp({
+  createdAt,
+  timestampFormat,
+  className,
+}: {
+  createdAt: string;
+  timestampFormat: TimestampFormat;
+  className?: string;
+}) {
+  return (
+    <Tooltip>
+      <TooltipTrigger
+        render={
+          <span
+            className={cn(
+              "pointer-events-none absolute me-1 shrink-0 whitespace-nowrap rounded-md text-muted-foreground text-xs tabular-nums opacity-0 group-hover/timeline-row:pointer-events-auto group-hover/timeline-row:static group-hover/timeline-row:opacity-100 group-focus-within/timeline-row:pointer-events-auto group-focus-within/timeline-row:static group-focus-within/timeline-row:opacity-100",
+              className,
+            )}
+          />
+        }
+      >
+        {formatDayAwareTimestamp(createdAt, timestampFormat)}
+      </TooltipTrigger>
+      <TooltipPopup>{formatChatTimestampTooltip(createdAt, timestampFormat)}</TooltipPopup>
+    </Tooltip>
+  );
+}
+
 function TurnFoldTimelineRow({ row }: { row: Extract<TimelineRow, { kind: "turn-fold" }> }) {
   const ctx = use(TimelineRowCtx);
   const Icon = row.expanded ? ChevronDownIcon : ChevronRightIcon;
 
   return (
-    <div className="border-b border-border/60 pb-2 pt-1">
+    <div className="group/timeline-row relative flex items-center gap-1 border-b border-border/60 pb-2 pe-0.5 pt-1">
       <button
         type="button"
         aria-expanded={row.expanded}
@@ -2079,6 +2116,11 @@ function TurnFoldTimelineRow({ row }: { row: Extract<TimelineRow, { kind: "turn-
         <span>{row.label}</span>
         <Icon className="size-3.5" />
       </button>
+      <TimelineRowTimestamp
+        createdAt={row.createdAt}
+        timestampFormat={ctx.timestampFormat}
+        className="ms-auto"
+      />
     </div>
   );
 }
@@ -2770,7 +2812,7 @@ function WorkGroupToggleTimelineRow({
   return (
     <button
       type="button"
-      className="group/tool-group flex min-h-6 w-full cursor-pointer items-center gap-1.5 rounded-md px-0.5 py-0.5 text-left text-sm leading-relaxed transition-colors duration-150 hover:bg-accent/20 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-ring/70"
+      className="group/tool-group group/timeline-row relative flex min-h-6 w-full cursor-pointer items-center gap-1.5 rounded-md px-0.5 py-0.5 text-left text-sm leading-relaxed transition-colors duration-150 hover:bg-accent/20 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-ring/70"
       aria-label={row.hasFailure ? `${row.summary}, tool call failed` : undefined}
       aria-expanded={row.expanded}
       onClick={() => ctx.onToggleWorkGroup(row.groupId, row.id)}
@@ -2786,6 +2828,7 @@ function WorkGroupToggleTimelineRow({
         />
       </span>
       <span className="min-w-0 flex-1 truncate text-secondary-label">{row.summary}</span>
+      <TimelineRowTimestamp createdAt={row.createdAt} timestampFormat={ctx.timestampFormat} />
     </button>
   );
 }
@@ -4234,7 +4277,7 @@ const PlainWorkEntryRow = memo(function PlainWorkEntryRow(props: {
   onToggleEntry?: ((collapsed: boolean) => void) | undefined;
 }) {
   const { workEntry, workspaceRoot, isExpandedToolGroupEntry, displayLabel } = props;
-  const { threadRef, onImageExpand } = use(TimelineRowCtx);
+  const { threadRef, onImageExpand, timestampFormat } = use(TimelineRowCtx);
   const groupView = use(WorkGroupViewCtx);
   const [expanded, setExpanded] = useState(
     () => groupView?.state.expandedEntries.has(workEntry.id) ?? false,
@@ -4336,7 +4379,7 @@ const PlainWorkEntryRow = memo(function PlainWorkEntryRow(props: {
   return (
     <div
       className={cn(
-        "flex flex-col rounded-md px-0.5 transition-colors",
+        "group/timeline-row relative flex flex-col rounded-md px-0.5 transition-colors",
         isExpandedToolGroupEntry ? "py-0" : "py-0.5",
         expanded && "mb-1",
         canExpand &&
@@ -4406,6 +4449,7 @@ const PlainWorkEntryRow = memo(function PlainWorkEntryRow(props: {
               )}
             />
           </span>
+          <TimelineRowTimestamp createdAt={workEntry.createdAt} timestampFormat={timestampFormat} />
         </div>
       </div>
       {expanded && viewedImage && threadRef ? (