diff --git a/extensions/phone-control/index.test.ts b/extensions/phone-control/index.test.ts
index f68b4695c64..dbc32bb7805 100644
--- a/extensions/phone-control/index.test.ts
+++ b/extensions/phone-control/index.test.ts
@@ -269,6 +269,25 @@ describe("phone-control plugin", () => {
     });
   });
 
+  it("rejects arm requests when the expiry would exceed a valid Date", async () => {
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date(8_640_000_000_000_000));
+    try {
+      await withRegisteredPhoneControl(async ({ command, writeConfigFile }) => {
+        const res = await command.handler({
+          ...createCommandContext("arm writes 30s"),
+          channel: "webchat",
+          gatewayClientScopes: ["operator.admin"],
+        });
+
+        expect(res?.text ?? "").toContain("Invalid duration");
+        expect(writeConfigFile).not.toHaveBeenCalled();
+      });
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
   it("allows external owner callers without gateway scopes to mutate phone control", async () => {
     await withRegisteredPhoneControl(async ({ command, writeConfigFile }) => {
       const res = await command.handler({
diff --git a/extensions/phone-control/index.ts b/extensions/phone-control/index.ts
index 085aa48dcc0..331d40e87dd 100644
--- a/extensions/phone-control/index.ts
+++ b/extensions/phone-control/index.ts
@@ -1,6 +1,10 @@
 import fs from "node:fs/promises";
 import path from "node:path";
 import type { OpenClawConfig } from "openclaw/plugin-sdk/config-contracts";
+import {
+  asDateTimestampMs,
+  resolveExpiresAtMsFromDurationMs,
+} from "openclaw/plugin-sdk/number-runtime";
 import { replaceFileAtomic } from "openclaw/plugin-sdk/security-runtime";
 import {
   normalizeLowercaseStringOrEmpty,
@@ -294,14 +298,38 @@ function lacksAdminToMutatePhoneControl(params: {
   return senderIsOwner !== true;
 }
 
+function resolveArmExpiryStatus(state: ArmStateFile, nowRaw = Date.now()): string {
+  if (state.expiresAtMs == null) {
+    return "manual disarm required";
+  }
+  const now = asDateTimestampMs(nowRaw);
+  if (now === undefined) {
+    return "expiry unavailable";
+  }
+  const expiresAt = asDateTimestampMs(state.expiresAtMs);
+  if (expiresAt === undefined || expiresAt <= now) {
+    return "expired";
+  }
+  return `expires in ${formatDuration(expiresAt - now)}`;
+}
+
+function isArmStateExpired(state: ArmStateFile, nowRaw = Date.now()): boolean {
+  if (state.expiresAtMs == null) {
+    return false;
+  }
+  const now = asDateTimestampMs(nowRaw);
+  if (now === undefined) {
+    return false;
+  }
+  const expiresAt = asDateTimestampMs(state.expiresAtMs);
+  return expiresAt === undefined || expiresAt <= now;
+}
+
 function formatStatus(state: ArmStateFile | null): string {
   if (!state) {
     return "Phone control: disarmed.";
   }
-  const until =
-    state.expiresAtMs == null
-      ? "manual disarm required"
-      : `expires in ${formatDuration(Math.max(0, state.expiresAtMs - Date.now()))}`;
+  const until = resolveArmExpiryStatus(state);
   const cmds = uniqSorted(
     state.version === 1
       ? state.removedFromDeny
@@ -329,7 +357,7 @@ export default definePluginEntry({
           if (!state || state.expiresAtMs == null) {
             return;
           }
-          if (Date.now() < state.expiresAtMs) {
+          if (!isArmStateExpired(state)) {
             return;
           }
           await disarmNow({
@@ -430,7 +458,14 @@ export default definePluginEntry({
           if (durationMs === null) {
             return { text: "Invalid duration. Use values like 30s, 10m, 2h, or 1d." };
           }
-          const expiresAtMs = Date.now() + durationMs;
+          const armedAtMs = asDateTimestampMs(Date.now());
+          const expiresAtMs =
+            armedAtMs === undefined
+              ? undefined
+              : resolveExpiresAtMsFromDurationMs(durationMs, { nowMs: armedAtMs });
+          if (armedAtMs === undefined || expiresAtMs === undefined) {
+            return { text: "Invalid duration. Use values like 30s, 10m, 2h, or 1d." };
+          }
 
           const commands = resolveCommandsForGroup(group);
           const cfg = api.runtime.config.current() as OpenClawConfig;
@@ -461,7 +496,7 @@ export default definePluginEntry({
 
           await writeArmState(statePath, {
             version: STATE_VERSION,
-            armedAtMs: Date.now(),
+            armedAtMs,
             expiresAtMs,
             group,
             armedCommands: uniqSorted(commands),