feat: convert AM516 lead times to workdays

capabilities/am516-delivery-prediction/docs/AM516自然日转工作日需求说明_给AR836_20260902.md

@@ -5,6 +5,8 @@
 **日期**：2026-09-02
 **目的**：将 AM516 交期预测输出的自然日转换为工作日，并据此得到最终交货日期。
 
+**当前临时处理**：因 AR836 排期较晚，AM516 飞书机器人先在 API 返回后的输出层执行同一换算；不修改 AR836 API 原始数据。待 API 正式提供工作日口径后，应移除本地临时换算，避免重复转换。
+
 ## 一、需求背景
 
 AM516 当前输出的是自然日交期。销售希望得到工作日口径的交期，即：

capabilities/am516-delivery-prediction/docs/acceptance_samples.md

@@ -14,6 +14,7 @@ Expected:
 
 - model parses successfully;
 - quantity is accepted;
+- the bot immediately replies with `👀` after the valid trigger is accepted and before the API query starts;
 - the controlled script uses the macOS system trust store and keeps TLS verification enabled;
 - no temporary TLS-bypass parameter is required for the normal happy path;
 - API script runs;
@@ -39,6 +40,18 @@ Expected:
 - record-table columns follow this order: 序号、记录时间、型号、推荐类型、差异项、API状态、AM516预测交期、可用库存、主导因素;
 - unavailable candidates remain in their original rule order and are recorded as `❌ 不存在` with unavailable result fields shown as `—`;
 
+## Sample 1B | Natural Days To Workdays
+
+Rules and expected results:
+
+- treat `AM516总交期`, or numeric `总交期` when the AM516 field is absent, as the original natural-day lead time `N`;
+- convert `N` with the approved quotient-and-remainder rule, including `r = 4` as one rest day and `r = 0` as no remainder workday;
+- exclude the local query date itself, then count the converted workdays using the configured China statutory workday calendar;
+- statutory holidays are excluded and official makeup weekend workdays are included;
+- for a query date of `2026-09-02`, `31` natural days convert to `22` workdays and produce `2026-10-09`;
+- output `2026-10-09（原始31个自然日，折算22个工作日）` instead of adding a separate National Day exception;
+- when counting reaches an unconfigured calendar year, do not silently fall back to a Monday-Friday estimate.
+
 ## Sample 1A | Continue With Other Candidates
 
 Preconditions:
@@ -59,6 +72,7 @@ is not required.
 
 Expected:
 
+- the bot immediately replies with `👀` after the continuation and active-context gates pass;
 - the bot reuses the active model and quantity only for that same sender and chat;
 - the bot queries candidate positions 5-8 in the unchanged rule order;
 - the original model and candidate positions 1-4 are not queried or displayed again;
@@ -83,6 +97,7 @@ eRob110H160I-FHM-18ET[V6]
 Expected:
 
 - bot stays silent;
+- no acknowledgement emoji is sent;
 - no API call is made;
 - no record is appended.
 

capabilities/am516-delivery-prediction/docs/runbook.md

@@ -8,20 +8,22 @@
 4. Confirm a separate trusted AR51 approval record explicitly covers `api.zeroerr-agent.com`, the AM516 use case, and API-key use.
 5. If that domain-and-permission record is absent, stop before any outbound request; a general functional-test approval is insufficient by itself.
 6. Use model recommendation rules to generate the complete ordered internal candidate pool.
-7. Run the controlled script for the original model baseline and only the first four candidate models.
-8. Summarize the current batch, state how many candidates remain, and invite the same sender to ask naturally for more when candidates remain; exact wording is not required.
-9. Append a non-secret record.
-10. Return Feishu-friendly text with the fixed disclaimer.
+7. Immediately reply with `👀` to acknowledge the valid request.
+8. Run the controlled script for the original model baseline and only the first four candidate models.
+9. Convert each numeric natural-day lead time to workdays with the approved quotient-and-remainder rule, then count those workdays from the local query date through the configured China statutory workday calendar. The query date itself is excluded.
+10. Summarize the current batch, including the original natural days, converted workdays, and calculated delivery date; state how many candidates remain and invite the same sender to ask naturally for more when candidates remain.
+11. Append a non-secret record.
+12. Return Feishu-friendly text with the fixed disclaimer.
 
 ## Candidate Continuation
 
 1. Accept a clear request for more candidates only from the same sender in the same Feishu chat as the active initial query. Equivalent expressions such as `还有吗`、`有没有别的`、`再推荐几个`、`继续`、`下一批` or `more candidates` are valid; no exact phrase is required.
 2. The in-memory continuation context expires after six hours and is cleared by a bridge restart. If no matching context exists, stay silent and require a new complete model-and-quantity query.
-3. Query the next four unqueried rule candidates; do not re-query the original baseline or any earlier candidate.
+3. Immediately reply with `👀`, then query the next four unqueried rule candidates; do not re-query the original baseline or any earlier candidate.
 4. Missing or unsupported candidates still consume their rule-order positions and remain under `不可用候选`.
 5. Append one record block for the models queried in this continuation batch, then state whether more candidates remain.
 6. A new complete model-and-quantity request replaces the earlier continuation context for that sender and chat.
-7. Keep the dual gate of continuation intent plus valid context: unrelated text such as `more interesting` or `继续查询英语例句` must not trigger the old query.
+7. Keep the dual gate of continuation intent plus valid context: unrelated text such as `more interesting` or `继续查询英语例句` must not trigger the old query or acknowledgement.
 
 ## Approved Script
 

capabilities/am516-delivery-prediction/skills/joint-module-leadtime-report/SKILL.md

@@ -44,8 +44,12 @@ Stop if:
 
 - Enter the query workflow only when one message contains exactly one complete,
   rule-valid eRob model and exactly one positive quantity.
+- After a valid initial query or valid same-conversation candidate continuation
+  passes this gate, immediately reply with `👀` before starting the API query so
+  the sender knows the request was received.
 - If the model or quantity is missing, invalid, multiple, or ambiguous, stay
-  silent: send no Feishu reply, make no API request, and append no record.
+  silent: send no acknowledgement or other Feishu reply, make no API request,
+  and append no record.
 - An @mention by itself does not bypass this content gate.
 - After a valid message passes the gate, API or runtime failures may still return
   the bounded internal error response defined by this capability.
@@ -89,9 +93,12 @@ Do not use temporary curl, WebFetch, or any API method outside the controlled sc
 
 ## Output Selection
 
-- Prefer `data.交期汇总.AM516预测交期` when the API returns it and AR51 confirms it is usable.
-- If AM516 fields are absent, use original API prediction and mark it as original algorithm reference.
-- If only total days are available, state the total days and ask for human review.
+- Prefer numeric `data.交期汇总.AM516总交期`; if it is absent, fall back to numeric `data.交期汇总.总交期`. Treat this value as the original natural-day lead time `N`.
+- Convert `N` with `(q, r) = divmod(N, 7)`: `r = 0` gives `q × 5`; `1 ≤ r ≤ 4` gives `q × 5 + MAX(r - 1, 0)`; `5 ≤ r ≤ 6` gives `q × 5 + r - 2`. The result is workday lead time `W`.
+- Starting from the local query date, exclude the query date itself and count forward `W` workdays using the configured China statutory calendar. Statutory holidays are not workdays, ordinary Saturdays and Sundays are not workdays, and official makeup Saturdays or Sundays are workdays.
+- The configured 2026 calendar follows `国办发明电〔2025〕7号`. If counting reaches a year whose official calendar is not configured, do not silently estimate a delivery date; mark that calendar year as pending.
+- Display the calculated delivery date together with both `N` and `W`, for example `2026-10-09（原始31个自然日，折算22个工作日）`.
+- Use `data.交期汇总.AM516预测交期` only as a fallback when the API does not return a usable whole-number natural-day lead time, and explicitly mark that no conversion was performed.
 
 ## Candidate Batch Rule
 
@@ -156,13 +163,13 @@ Use this field order for a successful Feishu report:
 总体判断：
 - 现货候选：{fully covered candidate or none}
 - 最快候选型号：{fastest candidate}
-- 最快候选交期：{predicted date and total days}
+- 最快候选交期：{calculated delivery date, original natural days, and converted workdays}
 - 是否完全覆盖数量：{yes / no / unavailable}
 - 主导因素：{main factor}
 
 1. {model}（{candidate type and reducer brand}）
 - 数量：{quantity}台
-- AM516预测交期：{date and total days}
+- AM516预测交期：{calculated delivery date}（原始{N}个自然日，折算{W}个工作日）
 - 可用库存/覆盖情况：{summary-level inventory and coverage only}
 - 主导因素：{main factor}
 - 推荐理由：{rule-based recommendation reason}

shared/runtime/feishu_bot_bridge.py

@@ -12,7 +12,7 @@ import threading
 import time
 import unicodedata
 from dataclasses import dataclass
-from datetime import datetime
+from datetime import date, datetime, timedelta
 from pathlib import Path
 from typing import Any
 
@@ -79,6 +79,43 @@ ALLOWED_VERSIONS = {
 }
 CANDIDATE_BATCH_SIZE = 4
 CANDIDATE_CONTINUATION_TTL_SECONDS = 6 * 60 * 60
+RECEIVED_ACKNOWLEDGEMENT = "👀"
+
+
+def _inclusive_date_range(start: date, end: date) -> frozenset[date]:
+    return frozenset(
+        start + timedelta(days=offset)
+        for offset in range((end - start).days + 1)
+    )
+
+
+# 国办发明电〔2025〕7号：国务院办公厅关于2026年部分节假日安排的通知。
+CHINA_WORKDAY_CALENDAR_SOURCE = (
+    "https://www.gov.cn/zhengce/zhengceku/202511/content_7047091.htm"
+)
+CHINA_OFFICIAL_HOLIDAYS = {
+    2026: frozenset().union(
+        _inclusive_date_range(date(2026, 1, 1), date(2026, 1, 3)),
+        _inclusive_date_range(date(2026, 2, 15), date(2026, 2, 23)),
+        _inclusive_date_range(date(2026, 4, 4), date(2026, 4, 6)),
+        _inclusive_date_range(date(2026, 5, 1), date(2026, 5, 5)),
+        _inclusive_date_range(date(2026, 6, 19), date(2026, 6, 21)),
+        _inclusive_date_range(date(2026, 9, 25), date(2026, 9, 27)),
+        _inclusive_date_range(date(2026, 10, 1), date(2026, 10, 7)),
+    )
+}
+CHINA_OFFICIAL_MAKEUP_WORKDAYS = {
+    2026: frozenset(
+        {
+            date(2026, 1, 4),
+            date(2026, 2, 14),
+            date(2026, 2, 28),
+            date(2026, 5, 9),
+            date(2026, 9, 20),
+            date(2026, 10, 10),
+        }
+    )
+}
 CANDIDATE_CONTINUATION_SHORT_PHRASES = {
     "还有吗",
     "还有呢",
@@ -172,6 +209,12 @@ class CandidateUnavailableError(RuntimeError):
     pass
 
 
+class WorkdayCalendarUnavailableError(ValueError):
+    def __init__(self, year: int) -> None:
+        self.year = year
+        super().__init__(f"{year}年国家法定工作日历未配置")
+
+
 _candidate_continuations: dict[str, CandidateContinuation] = {}
 _candidate_continuation_lock = threading.Lock()
 
@@ -493,13 +536,74 @@ def run_controlled_query(request: RequestInput) -> dict[str, Any]:
     return payload
 
 
-def lead_time_details(payload: dict[str, Any], requested_quantity: int) -> dict[str, Any]:
+def natural_days_to_workdays(natural_days: int) -> int:
+    """Convert natural days with AR51's fixed quotient-and-remainder rule."""
+    if isinstance(natural_days, bool) or not isinstance(natural_days, int):
+        raise TypeError("自然日交期必须是整数")
+    if natural_days < 0:
+        raise ValueError("自然日交期不能小于0")
+
+    full_weeks, remainder = divmod(natural_days, 7)
+    if remainder == 0:
+        remainder_workdays = 0
+    elif remainder <= 4:
+        remainder_workdays = max(remainder - 1, 0)
+    else:
+        remainder_workdays = remainder - 2
+    return full_weeks * 5 + remainder_workdays
+
+
+def is_china_official_workday(day: date) -> bool:
+    holidays = CHINA_OFFICIAL_HOLIDAYS.get(day.year)
+    makeup_workdays = CHINA_OFFICIAL_MAKEUP_WORKDAYS.get(day.year)
+    if holidays is None or makeup_workdays is None:
+        raise WorkdayCalendarUnavailableError(day.year)
+    if day in makeup_workdays:
+        return True
+    if day in holidays:
+        return False
+    return day.weekday() < 5
+
+
+def add_china_official_workdays(start: date, workdays: int) -> date:
+    """Count official workdays after start; the start date itself is excluded."""
+    if isinstance(workdays, bool) or not isinstance(workdays, int):
+        raise TypeError("工作日交期必须是整数")
+    if workdays < 0:
+        raise ValueError("工作日交期不能小于0")
+
+    current = start
+    counted = 0
+    while counted < workdays:
+        current += timedelta(days=1)
+        if is_china_official_workday(current):
+            counted += 1
+    return current
+
+
+def whole_natural_day_count(value: Any) -> int | None:
+    if isinstance(value, bool) or not isinstance(value, (int, float)):
+        return None
+    if isinstance(value, float) and not value.is_integer():
+        return None
+    result = int(value)
+    return result if result >= 0 else None
+
+
+def lead_time_details(
+    payload: dict[str, Any],
+    requested_quantity: int,
+    calculation_date: date | None = None,
+) -> dict[str, Any]:
+    calculation_date = calculation_date or datetime.now().astimezone().date()
     data = payload.get("data")
     if not isinstance(data, dict):
         return {
             "prediction": "接口未返回可用交期汇总，需人工复核。",
             "prediction_value": None,
             "total_days": None,
+            "workdays": None,
+            "delivery_date": None,
             "main_factor": "接口未返回，需人工复核",
             "inventory": "接口未返回可用库存汇总，需人工复核。",
             "available_inventory": None,
@@ -514,6 +618,8 @@ def lead_time_details(payload: dict[str, Any], requested_quantity: int) -> dict[
             "prediction": "接口未返回可用交期汇总，需人工复核。",
             "prediction_value": None,
             "total_days": None,
+            "workdays": None,
+            "delivery_date": None,
             "main_factor": "接口未返回，需人工复核",
             "inventory": "接口未返回可用库存汇总，需人工复核。",
             "available_inventory": None,
@@ -530,14 +636,28 @@ def lead_time_details(payload: dict[str, Any], requested_quantity: int) -> dict[
         else "接口未返回，需人工复核"
     )
     predicted_date = summary.get("AM516预测交期")
-    total_days = summary.get("AM516总交期", summary.get("总交期"))
-    if isinstance(predicted_date, (str, int, float)):
-        days_suffix = f"（{total_days}天）" if isinstance(total_days, (int, float)) else ""
-        prediction = f"AM516预测交期：{predicted_date}{days_suffix}"
-        prediction_value = str(predicted_date)
-    elif isinstance(total_days, (int, float)):
-        prediction = f"原算法总交期参考：{total_days}天"
-        prediction_value = f"{total_days}天"
+    total_days = whole_natural_day_count(summary.get("AM516总交期"))
+    if total_days is None:
+        total_days = whole_natural_day_count(summary.get("总交期"))
+    workdays: int | None = None
+    delivery_date: date | None = None
+    if total_days is not None:
+        workdays = natural_days_to_workdays(total_days)
+        try:
+            delivery_date = add_china_official_workdays(calculation_date, workdays)
+        except WorkdayCalendarUnavailableError as exc:
+            prediction_value = (
+                f"【{exc}】（原始{total_days}个自然日，折算{workdays}个工作日）"
+            )
+        else:
+            prediction_value = (
+                f"{delivery_date.isoformat()}"
+                f"（原始{total_days}个自然日，折算{workdays}个工作日）"
+            )
+        prediction = f"AM516预测交期：{prediction_value}"
+    elif isinstance(predicted_date, (str, int, float)):
+        prediction_value = f"{predicted_date}（接口未返回自然日交期，未换算）"
+        prediction = f"AM516预测交期：{prediction_value}"
     else:
         prediction = "接口未返回可用交期汇总，需人工复核。"
         prediction_value = None
@@ -616,7 +736,9 @@ def lead_time_details(payload: dict[str, Any], requested_quantity: int) -> dict[
     return {
         "prediction": prediction,
         "prediction_value": prediction_value,
-        "total_days": total_days if isinstance(total_days, (int, float)) else None,
+        "total_days": total_days,
+        "workdays": workdays,
+        "delivery_date": delivery_date.isoformat() if delivery_date else None,
         "main_factor": main_factor_text,
         "inventory": inventory_text,
         "available_inventory": (
@@ -642,8 +764,8 @@ def overall_judgment_lines(candidates: list[dict[str, Any]]) -> list[str]:
     fastest = min(
         available,
         key=lambda candidate: (
-            candidate["details"]["total_days"]
-            if candidate["details"]["total_days"] is not None
+            candidate["details"]["workdays"]
+            if candidate["details"]["workdays"] is not None
             else float("inf")
         ),
     )
@@ -814,6 +936,7 @@ def build_report(request: RequestInput, candidate_offset: int = 0) -> str:
     if candidate_offset < 0:
         raise InputError("候选批次位置无效，请重新发起型号和数量查询。")
 
+    calculation_date = datetime.now().astimezone().date()
     all_candidate_specs = generate_candidate_specs(request.model)
     candidate_specs = all_candidate_specs[
         candidate_offset : candidate_offset + CANDIDATE_BATCH_SIZE
@@ -826,7 +949,11 @@ def build_report(request: RequestInput, candidate_offset: int = 0) -> str:
     baseline: dict[str, Any] | None = None
     if is_initial_batch:
         baseline_payload = run_controlled_query(request)
-        baseline = lead_time_details(baseline_payload, request.quantity)
+        baseline = lead_time_details(
+            baseline_payload,
+            request.quantity,
+            calculation_date=calculation_date,
+        )
         if not baseline["has_lead_time"]:
             raise RuntimeError("原型号接口未返回可用交期汇总，未生成候选结果。")
         candidates.append(
@@ -849,7 +976,11 @@ def build_report(request: RequestInput, candidate_offset: int = 0) -> str:
             payload = run_controlled_query(RequestInput(spec["model"], request.quantity))
         except CandidateUnavailableError:
             return spec, None
-        details = lead_time_details(payload, request.quantity)
+        details = lead_time_details(
+            payload,
+            request.quantity,
+            calculation_date=calculation_date,
+        )
         return spec, details if details["has_lead_time"] else None
 
     if candidate_specs:
@@ -1029,6 +1160,35 @@ def reply(client: lark.Client, message_id: str, text: str) -> None:
     logging.info("Feishu reply sent: message_id=%s parts=%s", message_id, len(post_contents))
 
 
+def reply_received_acknowledgement(client: lark.Client, message_id: str) -> None:
+    request = (
+        lark.im.v1.ReplyMessageRequest.builder()
+        .message_id(message_id)
+        .request_body(
+            lark.im.v1.ReplyMessageRequestBody.builder()
+            .msg_type("text")
+            .content(
+                json.dumps(
+                    {"text": RECEIVED_ACKNOWLEDGEMENT},
+                    ensure_ascii=False,
+                )
+            )
+            .uuid(f"{message_id[:44]}-ack")
+            .build()
+        )
+        .build()
+    )
+    response = client.im.v1.message.reply(request)
+    if not response.success():
+        logging.error(
+            "Feishu acknowledgement failed: code=%s message_id=%s",
+            response.code,
+            message_id,
+        )
+        return
+    logging.info("Feishu acknowledgement sent: message_id=%s", message_id)
+
+
 _seen_message_ids: set[str] = set()
 _seen_message_lock = threading.Lock()
 
@@ -1055,6 +1215,8 @@ def handle_message(client: lark.Client, data: lark.im.v1.P2ImMessageReceiveV1) -
         )
         return
 
+    reply_received_acknowledgement(client, message_id)
+
     if continuation_state is None:
         clear_candidate_continuation(key)
 

tests/test_feishu_bot_bridge.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import sys
 import types
 import unittest
+from datetime import date
 from types import SimpleNamespace
 from unittest import mock
 
@@ -103,11 +104,16 @@ class TriggerGateTests(unittest.TestCase):
         with (
             mock.patch.object(bridge, "message_text", return_value="他怎么什么消息都回复啊"),
             mock.patch.object(bridge, "build_report") as build_report,
+            mock.patch.object(
+                bridge,
+                "reply_received_acknowledgement",
+            ) as acknowledge,
             mock.patch.object(bridge, "reply") as reply,
         ):
             bridge.handle_message(object(), data)
 
         build_report.assert_not_called()
+        acknowledge.assert_not_called()
         reply.assert_not_called()
 
     def test_valid_message_builds_and_replies(self) -> None:
@@ -121,11 +127,16 @@ class TriggerGateTests(unittest.TestCase):
                 "message_text",
                 return_value="eRob70H50I-BHM-18CTC[V5] 10台",
             ),
+            mock.patch.object(
+                bridge,
+                "reply_received_acknowledgement",
+            ) as acknowledge,
             mock.patch.object(bridge, "build_report", return_value="report") as build_report,
             mock.patch.object(bridge, "reply") as reply,
         ):
             bridge.handle_message("client", data)
 
+        acknowledge.assert_called_once_with("client", "om_valid")
         build_report.assert_called_once_with(
             bridge.RequestInput(model="eRob70H50I-BHM-18CTC[V5]", quantity=10)
         )
@@ -177,11 +188,16 @@ class TriggerGateTests(unittest.TestCase):
                 return_value="还有没有其他候选型号？",
             ),
             mock.patch.object(bridge, "build_report") as build_report,
+            mock.patch.object(
+                bridge,
+                "reply_received_acknowledgement",
+            ) as acknowledge,
             mock.patch.object(bridge, "reply") as reply,
         ):
             bridge.handle_message("client", data)
 
         build_report.assert_not_called()
+        acknowledge.assert_not_called()
         reply.assert_not_called()
 
     def test_follow_up_continues_from_fifth_candidate_in_same_conversation(self) -> None:
@@ -201,6 +217,10 @@ class TriggerGateTests(unittest.TestCase):
                 "build_report",
                 side_effect=["initial report", "continued report"],
             ) as build_report,
+            mock.patch.object(
+                bridge,
+                "reply_received_acknowledgement",
+            ) as acknowledge,
             mock.patch.object(bridge, "reply") as reply,
         ):
             bridge.handle_message("client", initial_data)
@@ -210,6 +230,13 @@ class TriggerGateTests(unittest.TestCase):
             build_report.call_args_list,
             [mock.call(request), mock.call(request, candidate_offset=4)],
         )
+        self.assertEqual(
+            acknowledge.call_args_list,
+            [
+                mock.call("client", "om_initial"),
+                mock.call("client", "om_follow_up"),
+            ],
+        )
         self.assertEqual(
             reply.call_args_list,
             [
@@ -229,6 +256,10 @@ class TriggerGateTests(unittest.TestCase):
                 "message_text",
                 side_effect=[request_text, "还有没有其他候选型号？"],
             ),
+            mock.patch.object(
+                bridge,
+                "reply_received_acknowledgement",
+            ) as acknowledge,
             mock.patch.object(bridge, "build_report", return_value="report") as build_report,
             mock.patch.object(bridge, "reply") as reply,
         ):
@@ -238,6 +269,7 @@ class TriggerGateTests(unittest.TestCase):
         build_report.assert_called_once_with(
             bridge.RequestInput(model="eRob70H50I-BHM-18CTC[V5]", quantity=10)
         )
+        acknowledge.assert_called_once_with("client", "om_small")
         reply.assert_called_once_with("client", "om_small", "report")
 
     def test_expired_candidate_context_is_removed(self) -> None:
@@ -313,5 +345,90 @@ class CandidateBatchTests(unittest.TestCase):
             self.assertNotIn(model, report)
 
 
+class WorkdayConversionTests(unittest.TestCase):
+    def test_natural_day_conversion_rule(self) -> None:
+        expected = {
+            0: 0,
+            1: 0,
+            2: 1,
+            3: 2,
+            4: 3,
+            5: 3,
+            6: 4,
+            7: 5,
+            18: 13,
+            23: 16,
+            26: 18,
+            31: 22,
+            33: 23,
+            36: 25,
+            43: 30,
+            48: 34,
+        }
+
+        for natural_days, workdays in expected.items():
+            with self.subTest(natural_days=natural_days):
+                self.assertEqual(
+                    bridge.natural_days_to_workdays(natural_days),
+                    workdays,
+                )
+
+    def test_2026_official_holiday_and_makeup_workdays(self) -> None:
+        self.assertTrue(bridge.is_china_official_workday(date(2026, 9, 20)))
+        self.assertFalse(bridge.is_china_official_workday(date(2026, 9, 25)))
+        self.assertFalse(bridge.is_china_official_workday(date(2026, 10, 1)))
+        self.assertTrue(bridge.is_china_official_workday(date(2026, 10, 10)))
+        self.assertFalse(bridge.is_china_official_workday(date(2026, 10, 11)))
+
+    def test_workday_dates_match_validation_samples(self) -> None:
+        start = date(2026, 9, 2)
+        samples = {
+            18: date(2026, 9, 20),
+            23: date(2026, 9, 23),
+            26: date(2026, 9, 28),
+            16: date(2026, 9, 17),
+            31: date(2026, 10, 9),
+            33: date(2026, 10, 10),
+            36: date(2026, 10, 13),
+            43: date(2026, 10, 20),
+            48: date(2026, 10, 26),
+        }
+
+        for natural_days, expected_date in samples.items():
+            with self.subTest(natural_days=natural_days):
+                workdays = bridge.natural_days_to_workdays(natural_days)
+                self.assertEqual(
+                    bridge.add_china_official_workdays(start, workdays),
+                    expected_date,
+                )
+
+    def test_api_natural_days_drive_displayed_delivery_date(self) -> None:
+        payload = successful_payload()
+        summary = payload["data"]["交期汇总"]
+        summary["AM516预测交期"] = "2026-10-03"
+        summary["AM516总交期"] = 31
+
+        details = bridge.lead_time_details(
+            payload,
+            requested_quantity=10,
+            calculation_date=date(2026, 9, 2),
+        )
+
+        self.assertEqual(details["total_days"], 31)
+        self.assertEqual(details["workdays"], 22)
+        self.assertEqual(details["delivery_date"], "2026-10-09")
+        self.assertEqual(
+            details["prediction"],
+            "AM516预测交期：2026-10-09（原始31个自然日，折算22个工作日）",
+        )
+
+    def test_unconfigured_calendar_year_is_not_silently_estimated(self) -> None:
+        with self.assertRaisesRegex(
+            bridge.WorkdayCalendarUnavailableError,
+            "2027年国家法定工作日历未配置",
+        ):
+            bridge.add_china_official_workdays(date(2026, 12, 31), 1)
+
+
 if __name__ == "__main__":
     unittest.main()