diff --git a/src/app/actions/reschedule.ts b/src/app/actions/reschedule.ts
new file mode 100644
index 0000000..856702f
--- /dev/null
+++ b/src/app/actions/reschedule.ts
@@ -0,0 +1,59 @@
+"use server";
+
+import { revalidatePath } from "next/cache";
+
+import { getServerPb } from "@/lib/pb/server";
+import { requireSession } from "@/lib/auth/session";
+import { logActivity } from "@/app/actions/activity";
+import type { CardRecord } from "@/lib/pb/types";
+
+const ISO_DATE = /^\d{4}-\d{2}-\d{2}$/;
+
+/**
+ * Move a card's target date from the timeline. Owner only.
+ *
+ * `target_date` is a CLIENT-OWNED field. The owner may write it — PocketBase
+ * permits it — but doing so silently would mean a developer moving a date the
+ * client chose with no record of it. The activity row below is what makes the
+ * client's card history read "Dave moved the target date from 1 Oct to 15 Nov",
+ * in their own view, without anyone having to tell them.
+ *
+ * Do not remove that call to make this faster.
+ */
+export async function rescheduleCardAction(input: {
+  cardId: string;
+  date: string;
+}): Promise<{ ok: boolean; message?: string }> {
+  const session = await requireSession();
+  if (session.role !== "owner") return { ok: false, message: "Not found" };
+
+  if (!ISO_DATE.test(input.date)) {
+    return { ok: false, message: "Invalid date" };
+  }
+
+  const pb = await getServerPb();
+
+  const card = await pb
+    .collection("cards")
+    .getOne<CardRecord>(input.cardId)
+    .catch(() => null);
+  if (!card) return { ok: false, message: "Card not found" };
+
+  const previous = (card.target_date ?? "").slice(0, 10);
+  if (previous === input.date) return { ok: true };
+
+  await pb.collection("cards").update(input.cardId, { target_date: input.date });
+
+  await logActivity({
+    project: card.project,
+    card: card.id,
+    actor: session.userId,
+    action: "date_changed",
+    field: "target_date",
+    oldValue: card.target_date ?? "",
+    newValue: input.date,
+  });
+
+  revalidatePath("/plan");
+  return { ok: true };
+}