feat(工作日): 新增工作小时计算工具 + 节假日表与管理接口

- time_utils 新增 to_beijing(统一naive按UTC转北京时间) + working_duration_hours(排除周末/节假日)
- Holiday 模型 + alembic 迁移建 holidays 表
- GET/POST/DELETE /holidays 节假日管理接口，可随时配置放假日期

backend/app/api/v1/endpoints/holidays.py

@@ -0,0 +1,60 @@
+"""节假日管理 — 工作日时长计算所需的放假日期配置"""
+from datetime import date
+from fastapi import APIRouter, Depends, HTTPException
+from pydantic import BaseModel, Field
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.core.database import get_db
+from app.models.holiday import Holiday
+from app.services.auth_service import get_current_user
+
+router = APIRouter(prefix="/holidays", tags=["节假日管理"])
+
+
+class HolidayCreate(BaseModel):
+    day: date = Field(..., description="放假日期")
+    name: str | None = Field(None, max_length=100, description="放假说明")
+
+
+@router.get("/")
+async def list_holidays(
+    db: AsyncSession = Depends(get_db),
+):
+    """获取全部放假日期（按日期正序）"""
+    result = await db.execute(select(Holiday).order_by(Holiday.day.asc()))
+    return [
+        {"id": h.id, "date": h.day.isoformat(), "name": h.name}
+        for h in result.scalars().all()
+    ]
+
+
+@router.post("/", status_code=201)
+async def create_holiday(
+    data: HolidayCreate,
+    db: AsyncSession = Depends(get_db),
+    current_user: dict = Depends(get_current_user),
+):
+    """添加一个放假日期"""
+    exists = await db.scalar(select(Holiday).where(Holiday.day == data.day))
+    if exists:
+        raise HTTPException(status_code=400, detail=f"{data.day} 已在节假日列表中")
+    h = Holiday(day=data.day, name=data.name)
+    db.add(h)
+    await db.commit()
+    await db.refresh(h)
+    return {"id": h.id, "date": h.day.isoformat(), "name": h.name}
+
+
+@router.delete("/{holiday_id}", status_code=204)
+async def delete_holiday(
+    holiday_id: int,
+    db: AsyncSession = Depends(get_db),
+    current_user: dict = Depends(get_current_user),
+):
+    """删除一个放假日期"""
+    h = await db.get(Holiday, holiday_id)
+    if not h:
+        raise HTTPException(status_code=404, detail="节假日不存在")
+    await db.delete(h)
+    await db.commit()

backend/app/api/v1/router.py

@@ -13,6 +13,7 @@ from app.api.v1.endpoints.records import router as records_router
 from app.api.v1.endpoints.notifications import router as notifications_router
 from app.api.v1.endpoints.app_version import router as app_version_router
 from app.api.v1.endpoints.analytics import router as analytics_router
+from app.api.v1.endpoints.holidays import router as holidays_router
 
 api_router = APIRouter()
 
@@ -29,3 +30,4 @@ api_router.include_router(records_router)
 api_router.include_router(notifications_router)
 api_router.include_router(app_version_router)
 api_router.include_router(analytics_router)
+api_router.include_router(holidays_router)

backend/app/core/time_utils.py

@@ -1,5 +1,5 @@
-"""全局北京时间 (UTC+8)"""
-from datetime import datetime
+"""全局北京时间 (UTC+8) 与工作日时长计算"""
+from datetime import datetime, date, time, timedelta, timezone
 from zoneinfo import ZoneInfo
 
 BEIJING_TZ = ZoneInfo("Asia/Shanghai")
@@ -8,3 +8,48 @@ BEIJING_TZ = ZoneInfo("Asia/Shanghai")
 def get_beijing_time() -> datetime:
     """返回当前北京时间"""
     return datetime.now(BEIJING_TZ)
+
+
+def to_beijing(dt: datetime | None) -> datetime | None:
+    """将任意 datetime 统一转为北京时间 aware。
+
+    - naive 时间按 UTC 处理（数据库 timestamptz 实存 UTC，SQLAlchemy 读出常为 naive）
+    - 带时区时间直接 astimezone 到北京
+    """
+    if dt is None:
+        return None
+    if dt.tzinfo is None:
+        return dt.replace(tzinfo=timezone.utc).astimezone(BEIJING_TZ)
+    return dt.astimezone(BEIJING_TZ)
+
+
+def working_duration_hours(
+    start: datetime | None,
+    end: datetime | None,
+    holidays: set[date] | None = None,
+) -> float:
+    """计算 start~end 之间排除周末与节假日的工作小时数。
+
+    - 周末（周六/周日）整天排除
+    - holidays 中配置的放假日期整天排除
+    - 其余日期按 24 小时连续计（一天内的时间都算）
+    - start/end 可为 naive（按 UTC 转）或 aware 北京时间
+    """
+    if not holidays:
+        holidays = set()
+    s = to_beijing(start)
+    e = to_beijing(end)
+    if s is None or e is None or e <= s:
+        return 0.0
+
+    total = 0.0
+    day = s.date()
+    last = e.date()
+    while day <= last:
+        if day.weekday() < 5 and day not in holidays:
+            seg_start = max(s, datetime.combine(day, time.min, tzinfo=BEIJING_TZ))
+            seg_end = min(e, datetime.combine(day, time.max, tzinfo=BEIJING_TZ))
+            if seg_end > seg_start:
+                total += (seg_end - seg_start).total_seconds() / 3600
+        day += timedelta(days=1)
+    return round(total, 1)

backend/app/models/__init__.py

@@ -7,6 +7,7 @@ from app.models.task_log import TaskLog
 from app.models.notification import Notification
 from app.models.app_version import AppVersion
 from app.models.message import ProductMessage
+from app.models.holiday import Holiday
 __all__ = [
     "Base",
     "ProductionOrder",
@@ -17,4 +18,5 @@ __all__ = [
     "Notification",
     "AppVersion",
     "ProductMessage",
+    "Holiday",
 ]

backend/app/models/holiday.py

@@ -0,0 +1,21 @@
+"""节假日模型 — 放假日期配置，用于工作日时长计算"""
+from datetime import date
+from sqlalchemy import Date, String
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.models.base import Base
+
+
+class Holiday(Base):
+    __tablename__ = "holidays"
+
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    day: Mapped[date] = mapped_column(
+        Date, unique=True, index=True, comment="放假日期",
+    )
+    name: Mapped[str | None] = mapped_column(
+        String(100), nullable=True, comment="放假说明（如国庆节）",
+    )
+
+    def __repr__(self) -> str:
+        return f"<Holiday {self.day}>"