diff --git a/backend/src/timeflow/intelligence/conversation/schedule_tools.py b/backend/src/timeflow/intelligence/conversation/schedule_tools.py
index 5baf61da..9815a52f 100644
--- a/backend/src/timeflow/intelligence/conversation/schedule_tools.py
+++ b/backend/src/timeflow/intelligence/conversation/schedule_tools.py
@@ -10,6 +10,7 @@
 from datetime import datetime
 from enum import StrEnum
 from typing import TYPE_CHECKING, Protocol, TypeVar, cast
+from zoneinfo import ZoneInfo
 
 from timeflow.business.calendar import (
     CreateScheduleCommand,
@@ -678,6 +679,7 @@ def _schedule_for_llm(snapshot: ScheduleSnapshot) -> dict[str, object]:
     Account scoping, status, timestamps, coordinates, and reminder disposition
     are internal noise that would bloat every turn's conversation history.
     """
+    tz = ZoneInfo(snapshot.timezone)
     return {
         "id": snapshot.id,
         "title": snapshot.title,
@@ -686,6 +688,7 @@ def _schedule_for_llm(snapshot: ScheduleSnapshot) -> dict[str, object]:
         "is_all_day": snapshot.is_all_day,
         "start_time": _iso_or_none(snapshot.start_time),
         "end_time": _iso_or_none(snapshot.end_time),
+        "starts_at_local": _local_text(snapshot.start_time, tz),
         "recurrence_rule": snapshot.recurrence_rule,
         "location_name": snapshot.location_name,
         "reminder_type": None if snapshot.reminder_type is None else snapshot.reminder_type.value,
@@ -695,6 +698,20 @@ def _schedule_for_llm(snapshot: ScheduleSnapshot) -> dict[str, object]:
     }
 
 
+def _local_text(instant: datetime | None, tz: ZoneInfo) -> str:
+    """Render a stored instant as local wall-clock text for the model to speak.
+
+    The ISO ``start_time`` keeps the exact offset for tool arguments, but the model
+    tends to read the clock digits verbatim when answering, ignoring the offset. A
+    UTC-stored instant (``10:00+00:00``) would then be spoken as "上午十点" instead of
+    the user's "下午六点". This companion field renders the same instant in the
+    schedule's own IANA zone, so the digits already match what the user meant.
+    """
+    if instant is None:
+        return ""
+    return instant.astimezone(tz).strftime("%Y-%m-%d %H:%M")
+
+
 def _iso_or_none(value: datetime | None) -> str | None:
     return None if value is None else value.isoformat()
 
diff --git a/backend/tests/intelligence/conversation/test_schedule_tools.py b/backend/tests/intelligence/conversation/test_schedule_tools.py
index 45dfac24..670b0769 100644
--- a/backend/tests/intelligence/conversation/test_schedule_tools.py
+++ b/backend/tests/intelligence/conversation/test_schedule_tools.py
@@ -7,6 +7,7 @@
 import threading
 from collections.abc import Callable, Mapping
 from datetime import UTC, datetime
+from zoneinfo import ZoneInfo
 
 import pytest
 
@@ -32,6 +33,7 @@
 )
 from timeflow.intelligence.conversation.schedule_tools import (
     ScheduleToolInputError,
+    _local_text,
     map_create_schedule_command,
     map_delete_schedule_command,
     map_find_schedules_query,
@@ -506,6 +508,29 @@ async def test_registry_calls_service_with_injected_account_and_serializes_snaps
     assert "category" not in result["result"]["schedules"][0]
 
 
+def test_local_text_renders_empty_for_a_schedule_without_a_start_time() -> None:
+    """A schedule without ``start_time`` (e.g. all-day or pending location) yields an
+    empty spoken field rather than a spurious wall-clock string."""
+    assert _local_text(None, ZoneInfo("Asia/Shanghai")) == ""
+
+
+@pytest.mark.asyncio
+async def test_serialized_snapshot_renders_local_wall_clock_for_the_model() -> None:
+    """The LLM-facing result adds a local wall-clock field so the model speaks the
+    user's clock digits, not the UTC digits it would otherwise read from the ISO.
+
+    FakeScheduleService stores ``07:00+00:00`` with timezone ``Asia/Shanghai``, so the
+    spoken field must render ``15:00`` -- the same instant on the user's clock."""
+    service = FakeScheduleService()
+    tool = build_agent_tool_registry(service, "account-1").get("schedule_create")
+
+    result = json.loads(await tool.execute(create_arguments()))
+
+    schedule = result["result"]["schedules"][0]
+    assert schedule["start_time"] == "2026-08-12T07:00:00+00:00"
+    assert schedule["starts_at_local"] == "2026-08-12 15:00"
+
+
 @pytest.mark.asyncio
 async def test_serialized_snapshot_trims_internal_fields() -> None:
     """The LLM-facing result keeps only reference/report fields and drops the