diff --git a/src/render/cesium/appRenderer.js b/src/render/cesium/appRenderer.js
index 2e87091b1..df11714bd 100644
--- a/src/render/cesium/appRenderer.js
+++ b/src/render/cesium/appRenderer.js
@@ -7,11 +7,10 @@
  * The renderer it makes is transitional. Its ports are the shared Cesium
  * ports (`ports.js`), the ones the conformance renderer is checked with,
  * less the members that would not be true of the application yet: the
- * globe (it draws photoreal tiles the port does not know), `whenSettled`
- * (it would not wait for them), `frame.setTime` (it would stop the
- * application's clock). Those arrive with the layer families that need
- * them (phase 2 of the renderer plan); `checkRendererShape` lists what is
- * still missing.
+ * globe (it draws photoreal tiles the port does not know) and
+ * `whenSettled` (it would not wait for them). Those arrive with the layer
+ * families that need them (phase 2 of the renderer plan);
+ * `checkRendererShape` lists what is still missing.
  * Until a family is ported, its code reaches the Cesium viewer through
  * `cesiumViewerOf`, never through a renderer member, so no engine type
  * crosses the contract and each call marks code still to port. Ported code
diff --git a/src/render/cesium/appRenderer.test.mjs b/src/render/cesium/appRenderer.test.mjs
index eb0cf71a0..b351b8d70 100644
--- a/src/render/cesium/appRenderer.test.mjs
+++ b/src/render/cesium/appRenderer.test.mjs
@@ -318,7 +318,6 @@ test('the application refuses a renderer it cannot run on, and destroys it', asy
 });
 
 const EXPECTED_MISSING = [
-  'frame.setTime',
   'renderer.globe',
   'renderer.readPixels',
   'renderer.releaseUnused',
diff --git a/src/render/cesium/ports.js b/src/render/cesium/ports.js
index 3a18938c4..4fd652a1b 100644
--- a/src/render/cesium/ports.js
+++ b/src/render/cesium/ports.js
@@ -347,6 +347,16 @@ export function createCesiumPorts(widget, { capabilities }) {
       targetFps = fps > 0 ? fps : 0;
       widget.targetFrameRate = targetFps || undefined;
     },
+    /**
+     * Moves the clock to `ms` and draws it. Whether the clock then runs on
+     * is its owner's: the application's clock keeps running if it was (a
+     * clock on Cesium's real-time step moves to its multiplier step, as
+     * setting its time does in Cesium).
+     */
+    setTime(ms) {
+      widget.clock.currentTime = Cesium.JulianDate.fromDate(new Date(ms));
+      frame.requestRender('time');
+    },
     time: () => Cesium.JulianDate.toDate(widget.clock.currentTime).getTime(),
   };
 
diff --git a/src/render/cesium/ports.test.mjs b/src/render/cesium/ports.test.mjs
index edd276e23..f2d4c571b 100644
--- a/src/render/cesium/ports.test.mjs
+++ b/src/render/cesium/ports.test.mjs
@@ -697,3 +697,18 @@ test('an icon draws its atlas slot once the atlas has it, and again when it chan
   );
   ports.dispose();
 });
+
+test('setTime moves scene time and draws it, leaving the clock running or not', () => {
+  const { widget, scene } = tickingWidget();
+  let requested = 0;
+  scene.requestRender = () => (requested += 1);
+  widget.clock.shouldAnimate = true;
+  const ports = createCesiumPorts(widget, { capabilities: all });
+  const t = Date.UTC(2026, 5, 21, 12);
+  ports.frame.setTime(t);
+  assert.equal(ports.frame.time(), t);
+  assert.equal(widget.clock.shouldAnimate, true, 'still running');
+  assert.equal(requested, 1, 'one frame asked for');
+  assert.deepEqual(ports.frame.diagnostics().pendingReasons, ['time']);
+  ports.dispose();
+});
diff --git a/src/render/cesium/sceneRenderer.js b/src/render/cesium/sceneRenderer.js
index 68514b986..1fa54cb4a 100644
--- a/src/render/cesium/sceneRenderer.js
+++ b/src/render/cesium/sceneRenderer.js
@@ -66,7 +66,8 @@ export async function createCesiumSceneRenderer({
     contextOptions: { webgl: { preserveDrawingBuffer: true } },
   });
   const scene = widget.scene;
-  // A fixed time, so lighting is the same in every capture.
+  // A fixed time, so lighting is the same in every capture; `setTime`
+  // moves it and it stays there.
   widget.clock.shouldAnimate = false;
   widget.clock.currentTime = Cesium.JulianDate.fromIso8601(
     '2026-06-21T18:00:00Z',
@@ -95,14 +96,6 @@ export async function createCesiumSceneRenderer({
     query: ports.query,
     report: ports.report,
   });
-  const frame = {
-    ...ports.frame,
-    setTime(ms) {
-      widget.clock.currentTime = Cesium.JulianDate.fromDate(new Date(ms));
-      widget.clock.shouldAnimate = false;
-      scene.requestRender();
-    },
-  };
 
   // --- Globe -----------------------------------------------------------------
 
@@ -269,7 +262,7 @@ export async function createCesiumSceneRenderer({
     contractVersion: '0',
     capabilities,
     canvas: scene.canvas,
-    frame,
+    frame: ports.frame,
     globe,
     // A member of a capability left out is absent, not stubbed.
     draw: capabilities.has('models')