feat(schedule): 任务支持「每天定时 / 每周定时」，用选择器而不是手写 cron

- schedule.py: 新增调度计算模块（纯函数，便于单测）。三种模式：interval（每 N 分钟）/ daily（选钟点）/ weekly（选星期 + 钟点）
- 钟点模式是「固定时刻」而非「固定延迟」——从日历重算，所以某轮跑晚了不会把之后每一轮都拖晚。interval 保持原语义：从上一轮开始计时
- 抖动只加给 interval。给「每天 9:00」也加抖动就成了 9:00–9:01 随机触发，操作者选的时间被悄悄改掉，只会像 bug
- 模型 / schema / service: 新增 schedule_mode / schedule_hours / schedule_days / schedule_minute。时钟字段存逗号分隔文本——几个小整数、永远整体读写，单开一张表只会换来 join。interval_minutes 保留且仍是默认值，已有任务不受影响
- service: 改动任何调度字段都按合并后的状态重算 next_run_at。重新启用也算改动，否则停用一个月再打开会带着一个月前的 next_run_at，一保存就立即触发
- 前端: 运行方式三选一 + 小时/星期胶囊多选 + 分钟下拉，并实时预览结果句子。任务卡片改显示后端拼好的 schedule_label，避免列表和编辑器对同一计划给出两种说法
- 校验: 钟点模式至少选一个时间，按周至少选一个星期

tests/test_schedule.py 新增 24 个用例，含「恰好等于当前时刻的档位归属下一天」这个会让调度器自循环的边界。

api/monitor/models.py

@@ -75,7 +75,7 @@ MODE_NOTE = "note"
 
 
 class MonitorTask(MonitorBase):
-    """One monitored schedule: a set of targets plus an interval."""
+    """One monitored schedule: a set of targets, plus when to run them."""
 
     __tablename__ = "monitor_task"
 
@@ -86,6 +86,21 @@ class MonitorTask(MonitorBase):
     enabled: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)
     interval_minutes: Mapped[int] = mapped_column(Integer, nullable=False, default=360)
 
+    # How the task is scheduled. `interval` is the original "every N minutes" and
+    # stays the default; `daily` and `weekly` fire at chosen clock times instead
+    # (the arithmetic lives in schedule.py).
+    #
+    # The clock fields are comma-separated text rather than a child table: they
+    # are a handful of small integers, always read as a whole, and a table would
+    # buy nothing but joins.
+    schedule_mode: Mapped[str] = mapped_column(String(16), nullable=False, default="interval")
+    # 0-23, e.g. "9,12,18". Empty in interval mode.
+    schedule_hours: Mapped[str] = mapped_column(String(96), nullable=False, default="")
+    # 0-6 with Monday = 0, matching Python's date.weekday(). Weekly mode only.
+    schedule_days: Mapped[str] = mapped_column(String(32), nullable=False, default="")
+    # Minute past the hour, shared by every time in the schedule.
+    schedule_minute: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+
     # Crawl window knobs, mirrored onto each run's CLI flags.
     max_notes_count: Mapped[int] = mapped_column(Integer, nullable=False, default=20)
     enable_comments: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)

api/monitor/schedule.py

@@ -0,0 +1,167 @@
+# -*- coding: utf-8 -*-
+# Copyright (c) 2025 [email protected]
+#
+# This file is part of MediaCrawler project.
+# Repository: https://github.com/NanmiCoder/MediaCrawler/blob/main/api/monitor/schedule.py
+# GitHub: https://github.com/NanmiCoder
+# Licensed under NON-COMMERCIAL LEARNING LICENSE 1.1
+#
+# 声明：本代码仅供学习和研究目的使用。使用者应遵守以下原则：
+# 1. 不得用于任何商业用途。
+# 2. 使用时应遵守目标平台的使用条款和robots.txt规则。
+# 3. 不得进行大规模爬取或对平台造成运营干扰。
+# 4. 应合理控制请求频率，避免给目标平台带来不必要的负担。
+# 5. 不得用于任何非法或不当的用途。
+#
+# 详细许可条款请参阅项目根目录下的LICENSE文件。
+# 使用本代码即表示您同意遵守上述原则和LICENSE中的所有条款。
+
+"""Monitor task schedule arithmetic.
+
+Three modes, all expressible by a picker. A raw cron string was ruled out on
+purpose -- it is a small language, and the operator should not have to write one
+to say "every day at nine":
+
+* ``interval`` -- every N minutes.
+* ``daily``    -- at chosen clock times, e.g. 09:00 and 18:30.
+* ``weekly``   -- at chosen clock times on chosen weekdays, e.g. Mon-Fri 10:00.
+
+The two clock modes are **fixed-time**, unlike ``interval``, which is fixed-delay.
+The distinction matters: for an interval, measuring the next slot from when the
+run starts is what stops a slow run from firing back-to-back. For a clock
+schedule it would be wrong, because a run that starts at 09:07 would drag every
+later run seven minutes late, compounding all day.
+
+Fixed-time also means **no jitter is applied** to clock schedules. The operator
+picked a time; quietly running at 09:04 instead of 09:00 is not a feature, it just
+looks like a bug. ``interval`` keeps its jitter, where there is no stated time to
+contradict.
+
+All arithmetic is in the server's local timezone -- naive datetimes on purpose,
+because the container is pinned to the operator's zone via TZ and pretending
+otherwise would add a timezone concept nobody asked for.
+"""
+
+from datetime import datetime, time, timedelta
+from typing import Optional, Sequence
+
+MODE_INTERVAL = "interval"
+MODE_DAILY = "daily"
+MODE_WEEKLY = "weekly"
+
+SCHEDULE_MODES = (MODE_INTERVAL, MODE_DAILY, MODE_WEEKLY)
+CLOCK_MODES = (MODE_DAILY, MODE_WEEKLY)
+
+_MS_PER_MINUTE = 60_000
+_WEEKDAY_NAMES = "一二三四五六日"
+
+
+def parse_hours(raw: Optional[str]) -> list[int]:
+    """``"9,18"`` -> ``[9, 18]``. Sorted, de-duplicated, junk dropped."""
+    return _parse_int_list(raw, 0, 23)
+
+
+def parse_days(raw: Optional[str]) -> list[int]:
+    """``"0,2,4"`` -> ``[0, 2, 4]``. **0 is Monday**, matching ``date.weekday()``."""
+    return _parse_int_list(raw, 0, 6)
+
+
+def _parse_int_list(raw: Optional[str], low: int, high: int) -> list[int]:
+    values: set[int] = set()
+    for chunk in (raw or "").split(","):
+        chunk = chunk.strip()
+        if not chunk:
+            continue
+        try:
+            number = int(chunk)
+        except ValueError:
+            # Stored values come from our own UI, but a hand-edited row must not
+            # be able to crash the scheduler loop.
+            continue
+        if low <= number <= high:
+            values.add(number)
+    return sorted(values)
+
+
+def format_hours(hours: Sequence[int]) -> str:
+    return ",".join(str(hour) for hour in sorted(set(hours)))
+
+
+def format_days(days: Sequence[int]) -> str:
+    return ",".join(str(day) for day in sorted(set(days)))
+
+
+def describe(
+    *,
+    mode: str,
+    interval_minutes: int,
+    hours: Sequence[int],
+    days: Sequence[int],
+    minute: int,
+) -> str:
+    """One human sentence for the task card.
+
+    Lives here rather than in the frontend so the list view and the editor cannot
+    drift apart on what a schedule means.
+    """
+    if mode == MODE_INTERVAL:
+        if interval_minutes % 1440 == 0:
+            return f"每 {interval_minutes // 1440} 天"
+        if interval_minutes % 60 == 0:
+            return f"每 {interval_minutes // 60} 小时"
+        return f"每 {interval_minutes} 分钟"
+
+    if not hours:
+        return "未设置时间"
+
+    clock = "、".join(f"{hour:02d}:{minute:02d}" for hour in sorted(set(hours)))
+
+    if mode == MODE_DAILY:
+        return f"每天 {clock}"
+
+    if not days:
+        return f"每天 {clock}"
+    labels = "、".join(f"周{_WEEKDAY_NAMES[day]}" for day in sorted(set(days)))
+    return f"{labels} {clock}"
+
+
+def next_occurrence(
+    *,
+    mode: str,
+    interval_minutes: int,
+    hours: Sequence[int],
+    days: Sequence[int],
+    minute: int,
+    after_ms: int,
+) -> Optional[int]:
+    """The next fire time strictly after ``after_ms``, as epoch milliseconds.
+
+    ``None`` means the schedule can never fire -- a clock mode with no hours
+    chosen. Callers store that as "no next run" rather than something in the past,
+    which would otherwise leave the task permanently due and re-running on every
+    tick.
+    """
+    if mode == MODE_INTERVAL:
+        return after_ms + max(1, interval_minutes) * _MS_PER_MINUTE
+
+    if not hours:
+        return None
+
+    now = datetime.fromtimestamp(after_ms / 1000)
+    # No weekdays chosen means every day, matching describe(). Without the `days`
+    # guard an empty selection would produce an empty allowed set, no matching day,
+    # and a task that silently never runs.
+    allowed_days = set(days) if (mode == MODE_WEEKLY and days) else set(range(7))
+
+    # Eight days of lookahead covers today's remaining slots plus a full week,
+    # which is more than any weekday selection can need.
+    for offset in range(8):
+        day = (now + timedelta(days=offset)).date()
+        if day.weekday() not in allowed_days:
+            continue
+        for hour in sorted(set(hours)):
+            candidate = datetime.combine(day, time(hour=hour, minute=minute))
+            if candidate > now:
+                return int(candidate.timestamp() * 1000)
+
+    return None

api/monitor/scheduler.py

@@ -23,8 +23,15 @@ is enough here: there is exactly one process, one global crawler subprocess, and
 therefore no concurrency to coordinate -- a cron-style library would add a
 dependency without adding a capability.
 
-Scheduling is **fixed-delay**, not fixed-rate: ``next_run_at`` is set from the
-moment a run starts, so a slow run cannot make its task fire back-to-back.
+Two families of schedule, and the difference matters:
+
+* ``interval`` is **fixed-delay**, not fixed-rate -- ``next_run_at`` is measured
+  from the moment a run starts, so a slow run cannot make its task fire
+  back-to-back.
+* the clock modes (``daily``/``weekly``) are **fixed-time** -- recomputed from the
+  calendar, so a run that starts late does not drag every later run with it.
+
+The arithmetic for both lives in schedule.py.
 """
 
 import asyncio
@@ -37,7 +44,7 @@ from sqlalchemy import select
 from tools.time_util import get_current_timestamp
 
 from ..services import crawler_manager
-from . import app_settings
+from . import app_settings, schedule
 from .db import get_session
 from .models import MonitorRun, MonitorTask, RUN_INTERRUPTED, RUN_RUNNING
 from .runner import execute_task
@@ -45,10 +52,9 @@ from .settings import get_cookie
 
 POLL_INTERVAL_SECONDS = 20
 # Spread tasks sharing an interval so they do not all come due on the same tick.
+# Applied to interval mode only -- see the advance step below.
 JITTER_SECONDS = 60
 
-_MS_PER_MINUTE = 60_000
-
 
 class MonitorScheduler:
     """Polls the task table and runs whatever is due."""
@@ -168,11 +174,34 @@ class MonitorScheduler:
             # Advance before running so a crash mid-run cannot cause an immediate
             # re-fire, and so a long outage coalesces into a single run instead
             # of one run per missed interval.
-            task.next_run_at = (
-                get_current_timestamp()
-                + task.interval_minutes * _MS_PER_MINUTE
-                + random.randint(0, JITTER_SECONDS) * 1000
+            now = get_current_timestamp()
+            following = schedule.next_occurrence(
+                mode=task.schedule_mode,
+                interval_minutes=task.interval_minutes,
+                hours=schedule.parse_hours(task.schedule_hours),
+                days=schedule.parse_days(task.schedule_days),
+                minute=task.schedule_minute,
+                after_ms=now,
             )
+
+            if following is None:
+                # A clock schedule with no times can never fire. The API rejects
+                # that shape, so this guards against a hand-edited row: park the
+                # task with no next run rather than leaving it permanently due and
+                # re-running it on every tick.
+                task.next_run_at = None
+                print(
+                    f"[monitor.scheduler] task {task.id} has no usable schedule "
+                    f"and will not run until one is set"
+                )
+            elif task.schedule_mode == schedule.MODE_INTERVAL:
+                # Jitter belongs to the interval mode only. Spreading identical
+                # intervals apart is the point; nudging a time the operator
+                # explicitly picked is not -- it just looks like a broken clock.
+                task.next_run_at = following + random.randint(0, JITTER_SECONDS) * 1000
+            else:
+                task.next_run_at = following
+
             task_id = task.id
 
         try:

api/monitor/service.py

@@ -28,7 +28,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 
 from tools.time_util import get_current_timestamp
 
-from . import app_settings, platforms
+from . import app_settings, platforms, schedule
 from .db import get_session
 from .platforms import PLATFORM_XHS
 from .models import (
@@ -53,6 +53,28 @@ _background_runs: set[asyncio.Task] = set()
 MIN_INTERVAL_MINUTES = 30
 MAX_INTERVAL_MINUTES = 7 * 24 * 60
 
+# Changing any of these invalidates the pending run slot.
+SCHEDULE_FIELDS = {
+    "interval_minutes",
+    "schedule_mode",
+    "schedule_hours",
+    "schedule_days",
+    "schedule_minute",
+}
+
+
+def _require_clock_fields(mode: str, hours: list, days: list) -> None:
+    """A clock schedule with no clock time can never fire.
+
+    The create schema already rejects that shape, but the update path merges
+    partial fields and therefore has no schema-level view of the result -- so the
+    check lives here, where both paths meet.
+    """
+    if mode in schedule.CLOCK_MODES and not hours:
+        raise ValueError("按钟点调度至少要选一个时间")
+    if mode == schedule.MODE_WEEKLY and not days:
+        raise ValueError("按周调度至少要选一个星期")
+
 _CREATOR_URL_RE = re.compile(r"xiaohongshu\.com/user/profile/([A-Za-z0-9_-]+)")
 _NOTE_URL_RE = re.compile(r"xiaohongshu\.com/(?:explore|discovery/item)/([A-Za-z0-9_-]+)")
 # XHS user ids and note ids are 24-char hex; allow a slightly wider range so a
@@ -139,7 +161,12 @@ async def create_task(session: AsyncSession, payload: Dict[str, Any]) -> Monitor
     # the Settings page actually governs new tasks.
     defaults = await app_settings.defaults(session, platform)
     interval_minutes = payload.get("interval_minutes") or defaults["interval_minutes"]
-    interval_ms = int(interval_minutes) * 60_000
+
+    schedule_mode = payload.get("schedule_mode") or schedule.MODE_INTERVAL
+    schedule_hours = list(payload.get("schedule_hours") or [])
+    schedule_days = list(payload.get("schedule_days") or [])
+    schedule_minute = int(payload.get("schedule_minute") or 0)
+    _require_clock_fields(schedule_mode, schedule_hours, schedule_days)
 
     task = MonitorTask(
         name=payload["name"],
@@ -147,12 +174,23 @@ async def create_task(session: AsyncSession, payload: Dict[str, Any]) -> Monitor
         mode=mode,
         enabled=payload.get("enabled", True),
         interval_minutes=interval_minutes,
+        schedule_mode=schedule_mode,
+        schedule_hours=schedule.format_hours(schedule_hours),
+        schedule_days=schedule.format_days(schedule_days),
+        schedule_minute=schedule_minute,
         max_notes_count=payload.get("max_notes_count") or defaults["max_notes_count"],
         enable_comments=payload.get("enable_comments", True),
         max_comments_count=payload.get("max_comments_count") or defaults["max_comments_count"],
         run_timeout_seconds=payload.get("run_timeout_seconds", 3600),
         notify_enabled=payload.get("notify_enabled", False),
-        next_run_at=now + interval_ms,
+        next_run_at=schedule.next_occurrence(
+            mode=schedule_mode,
+            interval_minutes=interval_minutes,
+            hours=schedule_hours,
+            days=schedule_days,
+            minute=schedule_minute,
+            after_ms=now,
+        ),
         last_status="idle",
         created_at=now,
         updated_at=now,
@@ -189,10 +227,14 @@ async def update_task(session: AsyncSession, task_id: int, payload: Dict[str, An
     if task is None:
         raise ValueError(f"Task {task_id} not found")
 
+    was_enabled = task.enabled
+
     for field in (
         "name",
         "enabled",
         "interval_minutes",
+        "schedule_mode",
+        "schedule_minute",
         "max_notes_count",
         "enable_comments",
         "max_comments_count",
@@ -202,6 +244,13 @@ async def update_task(session: AsyncSession, task_id: int, payload: Dict[str, An
         if field in payload and payload[field] is not None:
             setattr(task, field, payload[field])
 
+    # The clock lists are stored as comma-separated text, so they cannot go
+    # through the generic loop above.
+    if payload.get("schedule_hours") is not None:
+        task.schedule_hours = schedule.format_hours(payload["schedule_hours"])
+    if payload.get("schedule_days") is not None:
+        task.schedule_days = schedule.format_days(payload["schedule_days"])
+
     # Replacing targets resets the baseline implicitly: a note set that now
     # includes new ids will simply report them as new on the next run.
     if payload.get("targets") is not None:
@@ -227,8 +276,23 @@ async def update_task(session: AsyncSession, task_id: int, payload: Dict[str, An
                 )
             )
 
-    if "interval_minutes" in payload and payload["interval_minutes"]:
-        task.next_run_at = get_current_timestamp() + payload["interval_minutes"] * 60_000
+    # Any change to when the task runs invalidates the pending slot, so recompute
+    # it from the merged state rather than working out which field moved.
+    # Re-enabling counts as a change too: otherwise a task switched off for a
+    # month comes back holding a next_run_at a month in the past and fires the
+    # instant it is saved.
+    if (SCHEDULE_FIELDS & set(payload)) or (task.enabled and not was_enabled):
+        hours = schedule.parse_hours(task.schedule_hours)
+        days = schedule.parse_days(task.schedule_days)
+        _require_clock_fields(task.schedule_mode, hours, days)
+        task.next_run_at = schedule.next_occurrence(
+            mode=task.schedule_mode,
+            interval_minutes=task.interval_minutes,
+            hours=hours,
+            days=days,
+            minute=task.schedule_minute,
+            after_ms=get_current_timestamp(),
+        )
 
     task.updated_at = get_current_timestamp()
     await session.flush()
@@ -623,6 +687,7 @@ async def list_tasks(
             "mode": task.mode,
             "enabled": task.enabled,
             "interval_minutes": task.interval_minutes,
+            **_schedule_fields(task),
             "max_notes_count": task.max_notes_count,
             "enable_comments": task.enable_comments,
             "max_comments_count": task.max_comments_count,
@@ -644,6 +709,29 @@ async def list_tasks(
     ]
 
 
+def _schedule_fields(task: MonitorTask) -> Dict[str, Any]:
+    """The schedule columns, plus the sentence the task list renders.
+
+    The label is composed here rather than in the frontend so the list and the
+    editor cannot drift on what a given schedule means.
+    """
+    hours = schedule.parse_hours(task.schedule_hours)
+    days = schedule.parse_days(task.schedule_days)
+    return {
+        "schedule_mode": task.schedule_mode,
+        "schedule_hours": hours,
+        "schedule_days": days,
+        "schedule_minute": task.schedule_minute,
+        "schedule_label": schedule.describe(
+            mode=task.schedule_mode,
+            interval_minutes=task.interval_minutes,
+            hours=hours,
+            days=days,
+            minute=task.schedule_minute,
+        ),
+    }
+
+
 async def overview(session: AsyncSession, platform: Optional[str] = None) -> Dict[str, Any]:
     """Headline numbers for the dashboard tiles, scoped to one platform."""
     now = get_current_timestamp()