diff --git a/apps/web/src/components/settings/scheduledTasksSettings.logic.test.ts b/apps/web/src/components/settings/scheduledTasksSettings.logic.test.ts
index 2c96157e831f6..4d888cb986295 100644
--- a/apps/web/src/components/settings/scheduledTasksSettings.logic.test.ts
+++ b/apps/web/src/components/settings/scheduledTasksSettings.logic.test.ts
@@ -180,6 +180,16 @@ describe("fixed-time scheduled tasks", () => {
     });
     expect(draft.timeOfDay).toBe("09:05");
   });
+
+  it("keeps a fixed run time and rejects a cleared one", () => {
+    const draft = taskToDraft({
+      ...legacyTask,
+      schedule: { type: "fixed_time", timeOfDay: "14:30" },
+    });
+    expect(scheduleFromDraft(draft)).toEqual({ type: "fixed_time", timeOfDay: "14:30" });
+    // A native time input reports "" when it is cleared or only partly filled.
+    expect(scheduleFromDraft({ ...draft, timeOfDay: "" })).toBeNull();
+  });
 });
 
 describe("scheduled task destination", () => {
diff --git a/apps/web/src/components/settings/scheduledTasksSettings.logic.ts b/apps/web/src/components/settings/scheduledTasksSettings.logic.ts
index 26d83da69f428..4c29699ee7eb4 100644
--- a/apps/web/src/components/settings/scheduledTasksSettings.logic.ts
+++ b/apps/web/src/components/settings/scheduledTasksSettings.logic.ts
@@ -123,6 +123,8 @@ export function scheduleDraftErrors(draft: DraftState) {
       ];
     return [];
   }
+  if (draft.scheduleMode === "fixed" && !draft.timeOfDay)
+    return [{ title: "Invalid run time", description: "Pick a time." }];
   if (draft.scheduleMode !== "webhook") return [];
   if (parseMaxDeliveryAge(draft.maxDeliveryAgeMinutes) === undefined)
     return [
@@ -233,7 +235,7 @@ export function scheduleFromDraft(draft: DraftState): ScheduledTaskUpsertSchedul
   const selectedEveryDay = draft.weekdays.size === 0 || draft.weekdays.size === 7;
   return {
     type: "fixed_time",
-    timeOfDay: draft.timeOfDay || "09:00",
+    timeOfDay: draft.timeOfDay,
     ...(selectedEveryDay ? {} : { weekdays: [...draft.weekdays].toSorted() }),
   };
 }