[verified] feat: support monthly completion recurrence

backend/backup/service.py

@@ -354,6 +354,9 @@ def _validate_recurrence_graph(parsed: ParsedArchive) -> None:
                 "rrule": row.get("rrule"),
                 "trigger_mode": row.get("trigger_mode", "scheduled"),
                 "after_completion_days": row.get("after_completion_days"),
+                "after_completion_unit": row.get("after_completion_unit")
+                if row.get("trigger_mode", "scheduled") == "after_completion"
+                else None,
             })
             starts_at = datetime.fromisoformat(row["starts_at"])
             ends_at = datetime.fromisoformat(row["ends_at"]) if row.get("ends_at") else None
@@ -523,6 +526,8 @@ def _coerce(model, raw: dict, mapping: dict[str, dict[str, UUID]], user_id: UUID
                 elif isinstance(effective_type, Date) and isinstance(value, str):
                     value = date.fromisoformat(value)
             values[name] = value
+    if model is RecurrenceTemplate and "after_completion_unit" not in raw:
+        values["after_completion_unit"] = "days" if raw.get("trigger_mode") == "after_completion" else None
     return values
 
 

backend/main.py

@@ -999,7 +999,7 @@ async def create_task(
         from .mvp import parse_rrule
         if payload.rrule:
             parse_rrule(payload.rrule)
-    data = payload.model_dump(exclude={"rrule", "trigger_mode", "after_completion_days"})
+    data = payload.model_dump(exclude={"rrule", "trigger_mode", "after_completion_days", "after_completion_unit"})
     parent_filter = Task.parent_id == payload.parent_id if payload.parent_id else Task.parent_id.is_(None)
     max_position = await db.scalar(select(func.max(Task.position)).where(
         Task.user_id == user.id,
@@ -1019,6 +1019,9 @@ async def create_task(
                 starts_at=task.due_at,
                 trigger_mode=payload.trigger_mode or "scheduled",
                 after_completion_days=payload.after_completion_days,
+                after_completion_unit=(payload.after_completion_unit or "days")
+                if payload.trigger_mode == "after_completion"
+                else None,
             )
         )
     audit(db, user.id, "create", "task", task.id)

backend/models.py

@@ -154,6 +154,7 @@ class RecurrenceTemplate(Base):
     ends_at: Mapped[datetime | None] = mapped_column(UTCDateTime(), nullable=True)
     trigger_mode: Mapped[str] = mapped_column(String(32), default="scheduled")
     after_completion_days: Mapped[int | None] = mapped_column(Integer, nullable=True)
+    after_completion_unit: Mapped[str | None] = mapped_column(String(8), nullable=True)
     last_completed_at: Mapped[datetime | None] = mapped_column(UTCDateTime(), nullable=True)
     created_at: Mapped[datetime] = mapped_column(UTCDateTime(), default=utcnow)
 

backend/mvp.py

@@ -251,17 +251,22 @@ class RecurrenceCreate(BaseModel):
     rrule: str | None = Field(default=None, min_length=5, max_length=1000)
     trigger_mode: str = Field(default="scheduled", pattern="^(scheduled|after_completion)$")
     after_completion_days: int | None = Field(default=None, ge=1, le=3650)
+    after_completion_unit: str | None = Field(default=None, pattern="^(days|months)$")
 
     @model_validator(mode="after")
     def validate_mode(self):
         if self.trigger_mode == "scheduled" and (
-            self.rrule is None or self.after_completion_days is not None
+            self.rrule is None
+            or self.after_completion_days is not None
+            or self.after_completion_unit is not None
         ):
             raise ValueError("scheduled recurrence requires rrule and no completion interval")
         if self.trigger_mode == "after_completion" and (
             self.after_completion_days is None or self.rrule is not None
         ):
             raise ValueError("after_completion requires days and no rrule")
+        if self.trigger_mode == "after_completion" and self.after_completion_unit is None:
+            self.after_completion_unit = "days"
         return self
 
 
@@ -271,6 +276,7 @@ class RecurrenceChange(BaseModel):
     rrule: str | None = None
     trigger_mode: str | None = Field(default=None, pattern="^(scheduled|after_completion)$")
     after_completion_days: int | None = Field(default=None, ge=1, le=3650)
+    after_completion_unit: str | None = Field(default=None, pattern="^(days|months)$")
 
 
 class OccurrenceComplete(BaseModel):
@@ -430,6 +436,7 @@ async def get_task_recurrence(task_id: UUID, user: User = Depends(current_user),
         "ends_at": row.ends_at,
         "trigger_mode": row.trigger_mode,
         "after_completion_days": row.after_completion_days,
+        "after_completion_unit": row.after_completion_unit,
         "last_completed_at": row.last_completed_at,
     }
 
@@ -452,6 +459,9 @@ async def create_recurrence(payload: RecurrenceCreate, user: User = Depends(curr
         starts_at=task.due_at,
         trigger_mode=payload.trigger_mode,
         after_completion_days=payload.after_completion_days,
+        after_completion_unit=(payload.after_completion_unit or "days")
+        if payload.trigger_mode == "after_completion"
+        else None,
     )
     db.add(row)
     await db.commit(); await db.refresh(row)
@@ -463,6 +473,7 @@ async def create_recurrence(payload: RecurrenceCreate, user: User = Depends(curr
         "ends_at": row.ends_at,
         "trigger_mode": row.trigger_mode,
         "after_completion_days": row.after_completion_days,
+        "after_completion_unit": row.after_completion_unit,
         "last_completed_at": row.last_completed_at,
     }
 
@@ -504,12 +515,18 @@ async def edit_recurrence(recurrence_id: UUID, payload: RecurrenceChange, scope:
             if "after_completion_days" in payload.model_fields_set
             else template.after_completion_days
         )
+        requested_unit = (
+            payload.after_completion_unit
+            if "after_completion_unit" in payload.model_fields_set
+            else template.after_completion_unit
+        )
         requested_rrule = payload.rrule if payload.rrule is not None else template.rrule
         if requested_mode == "after_completion":
             if requested_days is None:
                 raise HTTPException(422, "完成后重复需要间隔天数")
             template.trigger_mode = requested_mode
             template.after_completion_days = requested_days
+            template.after_completion_unit = requested_unit or "days"
             template.rrule = None
         else:
             if requested_rrule is None:
@@ -517,6 +534,7 @@ async def edit_recurrence(recurrence_id: UUID, payload: RecurrenceChange, scope:
             parse_rrule(requested_rrule)
             template.trigger_mode = requested_mode
             template.after_completion_days = None
+            template.after_completion_unit = None
             template.rrule = requested_rrule.upper()
         if payload.title is not None:
             task.title = payload.title
@@ -533,6 +551,7 @@ async def edit_recurrence(recurrence_id: UUID, payload: RecurrenceChange, scope:
         "ends_at": template.ends_at,
         "trigger_mode": template.trigger_mode,
         "after_completion_days": template.after_completion_days,
+        "after_completion_unit": template.after_completion_unit,
         "last_completed_at": template.last_completed_at,
     }
 
@@ -1358,7 +1377,7 @@ def _export_payload(folders, lists, tasks, recurrences, habits, countdowns, memo
         "folders": [serialize(x, ["id", "name", "position", "deleted_at"]) for x in folders],
         "lists": [serialize(x, ["id", "folder_id", "name", "is_inbox", "position", "deleted_at"]) for x in lists],
         "tasks": [serialize(x, ["id", "list_id", "parent_id", "title", "description", "priority", "completed", "completed_at", "due_at", "due_has_time", "external_id", "deleted_at"]) for x in tasks],
-        "recurrences": [serialize(x, ["id", "task_id", "rrule", "starts_at", "ends_at", "trigger_mode", "after_completion_days", "last_completed_at"]) for x in recurrences],
+        "recurrences": [serialize(x, ["id", "task_id", "rrule", "starts_at", "ends_at", "trigger_mode", "after_completion_days", "after_completion_unit", "last_completed_at"]) for x in recurrences],
         "habits": [serialize(x, ["id", "name", "kind", "target", "max_value", "schedule_type", "weekdays", "month_days", "interval_days", "start_date", "archived_at", "position"]) for x in habits],
         "countdowns": [serialize(x, ["id", "title", "event_date", "calendar_mode", "lunar_month", "lunar_day", "ignore_year", "kind", "repeat_rule", "icon", "pinned", "archived_at", "created_at", "updated_at"]) for x in countdowns],
         "memos": [serialize(x, ["id", "title", "content", "version", "created_at", "updated_at", "deleted_at"]) for x in memos],
@@ -1570,11 +1589,17 @@ async def restore_json(payload: dict, mode: str = Query("merge", pattern="^(merg
         rrule = raw.get("rrule")
         if trigger_mode not in {"scheduled", "after_completion"}:
             raise HTTPException(422, "无效的重复触发模式")
+        unit = raw.get("after_completion_unit")
+        if unit is not None and unit not in {"days", "months"}:
+            raise HTTPException(422, "无效的完成后重复单位")
         if trigger_mode == "after_completion":
             if not isinstance(days, int) or isinstance(days, bool) or not 1 <= days <= 3650 or rrule is not None:
                 raise HTTPException(422, "无效的完成后重复备份")
-        elif not isinstance(rrule, str):
-            raise HTTPException(422, "定期重复缺少 RRULE")
+            unit = unit or "days"
+        else:
+            if not isinstance(rrule, str) or days is not None or unit is not None:
+                raise HTTPException(422, "定期重复备份包含无效字段")
+            unit = None
         db.add(RecurrenceTemplate(
             user_id=user.id,
             task_id=task_id,
@@ -1583,6 +1608,7 @@ async def restore_json(payload: dict, mode: str = Query("merge", pattern="^(merg
             ends_at=datetime.fromisoformat(raw["ends_at"]) if raw.get("ends_at") else None,
             trigger_mode=trigger_mode,
             after_completion_days=days,
+            after_completion_unit=unit,
             last_completed_at=datetime.fromisoformat(raw["last_completed_at"])
             if raw.get("last_completed_at") else None,
         ))

backend/recurrence_service.py

@@ -2,6 +2,7 @@ from datetime import UTC, datetime, time, timedelta
 from uuid import UUID
 from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
 
+from dateutil.relativedelta import relativedelta
 from fastapi import HTTPException
 from sqlalchemy import select, update
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -25,10 +26,15 @@ def _user_zone(user: User) -> ZoneInfo:
         raise HTTPException(422, "用户时区无效") from exc
 
 
-def _after_completion_due(task: Task, completed_at: datetime, days: int, user: User) -> datetime:
+def _after_completion_due(
+    task: Task, completed_at: datetime, value: int, unit: str | None, user: User
+) -> datetime:
     zone = _user_zone(user)
     completed_local = completed_at.astimezone(zone)
-    target_date = completed_local.date() + timedelta(days=days)
+    if unit == "months":
+        target_date = completed_local.date() + relativedelta(months=value)
+    else:
+        target_date = completed_local.date() + timedelta(days=value)
     if task.due_has_time:
         due_local = task.due_at.astimezone(zone)
         wall_time = due_local.timetz().replace(tzinfo=None)
@@ -67,7 +73,11 @@ async def apply_task_changes(
         if recurrence.trigger_mode == "after_completion":
             completed_at = utcnow()
             next_due = _after_completion_due(
-                task, completed_at, recurrence.after_completion_days, user
+                task,
+                completed_at,
+                recurrence.after_completion_days,
+                recurrence.after_completion_unit,
+                user,
             )
             changes["completed"] = False
             changes["due_at"] = next_due

backend/schemas.py

@@ -125,6 +125,7 @@ class TaskCreate(BaseModel):
     rrule: str | None = Field(default=None, min_length=5, max_length=1000)
     trigger_mode: str | None = Field(default=None, pattern="^(scheduled|after_completion)$")
     after_completion_days: int | None = Field(default=None, ge=1, le=3650)
+    after_completion_unit: str | None = Field(default=None, pattern="^(days|months)$")
 
     @field_validator("title")
     @classmethod
@@ -136,7 +137,12 @@ class TaskCreate(BaseModel):
 
     @model_validator(mode="after")
     def validate_recurrence(self):
-        has_recurrence = self.rrule is not None or self.trigger_mode is not None or self.after_completion_days is not None
+        has_recurrence = (
+            self.rrule is not None
+            or self.trigger_mode is not None
+            or self.after_completion_days is not None
+            or self.after_completion_unit is not None
+        )
         if has_recurrence and self.due_at is None:
             raise ValueError("recurrence requires due_at")
         if has_recurrence and self.parent_id is not None:
@@ -144,10 +150,15 @@ class TaskCreate(BaseModel):
         if self.trigger_mode == "after_completion":
             if self.after_completion_days is None or self.rrule is not None:
                 raise ValueError("after_completion requires days and no rrule")
-        elif self.trigger_mode == "scheduled" and self.rrule is None:
-            raise ValueError("scheduled recurrence requires rrule")
-        elif self.trigger_mode is None and self.after_completion_days is not None:
-            raise ValueError("after_completion_days requires after_completion mode")
+        elif self.trigger_mode == "scheduled":
+            if (
+                self.rrule is None
+                or self.after_completion_days is not None
+                or self.after_completion_unit is not None
+            ):
+                raise ValueError("scheduled recurrence requires rrule and no completion interval")
+        elif self.after_completion_days is not None or self.after_completion_unit is not None:
+            raise ValueError("completion interval requires after_completion mode")
         return self
 
 

frontend/src/App.vue

@@ -5,7 +5,7 @@ import {
   Ellipsis, GripVertical, Heading2, Inbox, Italic, Link, List, ListChecks, ListOrdered, ListTodo, Menu, Pencil, Plus, Quote,
   Settings, Trash2, X, Repeat2, StickyNote,
 } from 'lucide-vue-next'
-import { applyMarkdownFormat, buildTaskDueDraft, buildTaskRecurrencePayload, defaultTaskDueAt, fromDateTimeLocal, groupTaskTree, isSameTaskSortTier, moveItemWithinScope, parseTaskDueDraft, parseTaskRecurrence, parseTaskRrule, renderMarkdown, type MarkdownFormat, type TaskRepeatConfig, type TaskRepeatOption } from './lib/task-utils'
+import { applyMarkdownFormat, buildTaskDueDraft, buildTaskRecurrencePayload, defaultTaskDueAt, fromDateTimeLocal, groupTaskTree, isSameTaskSortTier, moveItemWithinScope, parseTaskDueDraft, parseTaskRecurrence, parseTaskRrule, renderMarkdown, type AfterCompletionUnit, type MarkdownFormat, type TaskRepeatConfig, type TaskRepeatOption } from './lib/task-utils'
 import { beginLatestRequest, createMutationReconciler, createTaskCompletionExitCoordinator, createTaskToggleCoordinator, formatApiErrorDetail, isLatestRequest, isTaskView, loadCountdownCache, mergeTaskToggleResponse, normalizeRequiredName, readStoredBoolean, readStoredNavigation, reconcileCurrentTaskView, runLatestRequest, shouldToggleRowSwipe, startPrimaryWithBackground, taskVersionedPatchPayload, writeStoredBoolean, writeStoredNavigation } from './lib/mvp-utils'
 import { csrfHeader } from './lib/csrf'
 import { createCompletionPulse, shouldAnimateCompletionExit, waitForCompletionExit } from './lib/completion-motion'
@@ -32,7 +32,7 @@ type FolderItem = { id: string; name: string }
 type TaskList = { id: string; folder_id: string | null; name: string; is_inbox: boolean }
 type Task = { id: string; list_id: string; parent_id: string | null; title: string; description: string; priority: number; completed: boolean; completed_at: string | null; version: number; due_at: string | null; due_has_time: boolean; subtasks?: Task[] }
 type RepeatOption = TaskRepeatOption
-type Recurrence = { id: string; task_id: string; rrule: string | null; trigger_mode: 'scheduled' | 'after_completion'; after_completion_days: number | null }
+type Recurrence = { id: string; task_id: string; rrule: string | null; trigger_mode: 'scheduled' | 'after_completion'; after_completion_days: number | null; after_completion_unit: AfterCompletionUnit | null }
 type View = 'tasks' | 'today' | 'upcoming' | 'trash' | 'habits' | 'countdowns' | 'memos' | 'calendar' | 'settings'
 
 const initialized = ref<boolean | null>(null)
@@ -158,9 +158,11 @@ const composePriority = ref(0)
 const composeDescription = ref('')
 const composeRepeat = ref<RepeatOption>('none')
 const composeAfterCompletionDays = ref('1')
+const composeAfterCompletionUnit = ref<AfterCompletionUnit>('days')
 const composeRepeatError = ref('')
 const selectedTaskRepeat = ref<RepeatOption>('none')
 const selectedAfterCompletionDays = ref('1')
+const selectedAfterCompletionUnit = ref<AfterCompletionUnit>('days')
 const selectedRepeatError = ref('')
 const selectedTaskRecurrence = ref<Recurrence | null>(null)
 const recurrenceLoading = ref(false)
@@ -205,6 +207,7 @@ function openTaskCompose() {
   composeDescription.value = ''
   composeRepeat.value = 'none'
   composeAfterCompletionDays.value = '1'
+  composeAfterCompletionUnit.value = 'days'
   composeRepeatError.value = ''
   composeRepeatConfig.value = defaultRepeatConfig()
   composeCalendarOpen.value = false
@@ -243,13 +246,13 @@ function activateFloatingAdd(origin: { x: number; y: number }) {
   else if (activeView.value === 'memos') void memoPanel.value?.createMemo()
   else if (['tasks', 'today', 'upcoming'].includes(activeView.value)) openTaskCompose()
 }
-async function saveRepeat(task: Task, value: RepeatOption, config: TaskRepeatConfig, afterCompletionDays: string, recurrence: Recurrence | null) {
+async function saveRepeat(task: Task, value: RepeatOption, config: TaskRepeatConfig, afterCompletionDays: string, afterCompletionUnit: AfterCompletionUnit, recurrence: Recurrence | null) {
   if (value !== 'none' && !task.due_at) throw new Error('请先设置截止时间')
   if (value === 'none') {
     if (recurrence) await api(`/recurrences/${recurrence.id}`, { method: 'DELETE' })
     return null
   }
-  const recurrencePayload = buildTaskRecurrencePayload(value, { afterCompletionDays, repeatConfig: config })
+  const recurrencePayload = buildTaskRecurrencePayload(value, { afterCompletionDays, afterCompletionUnit, repeatConfig: config })
   if (recurrence) {
     return await api(`/recurrences/${recurrence.id}`, { method: 'PATCH', body: JSON.stringify(recurrencePayload) }) as Recurrence
   }
@@ -263,6 +266,7 @@ async function loadTaskRecurrence(task: Task) {
   selectedTaskRecurrence.value = null
   selectedTaskRepeat.value = 'none'
   selectedAfterCompletionDays.value = '1'
+  selectedAfterCompletionUnit.value = 'days'
   selectedRepeatError.value = ''
   try {
     const recurrence = await api(`/tasks/${task.id}/recurrence`) as Recurrence | null
@@ -271,6 +275,7 @@ async function loadTaskRecurrence(task: Task) {
     const parsed = parseTaskRecurrence(recurrence)
     selectedTaskRepeat.value = parsed.option
     selectedAfterCompletionDays.value = String(parsed.afterCompletionDays)
+    selectedAfterCompletionUnit.value = parsed.afterCompletionUnit
     selectedRepeatConfig.value = recurrence?.rrule ? parseTaskRrule(recurrence.rrule) : defaultRepeatConfig()
   } catch (reason) {
     if (selectionIsCurrent()) fail(reason)
@@ -293,7 +298,7 @@ async function submitTaskCompose() {
   const targetListId = composeListId.value
   creatingTask.value = true
   try {
-    const recurrencePayload = buildTaskRecurrencePayload(composeRepeat.value, { afterCompletionDays: composeAfterCompletionDays.value, repeatConfig: composeRepeatConfig.value })
+    const recurrencePayload = buildTaskRecurrencePayload(composeRepeat.value, { afterCompletionDays: composeAfterCompletionDays.value, afterCompletionUnit: composeAfterCompletionUnit.value, repeatConfig: composeRepeatConfig.value })
     const dueValue = composeDueAt.value ? `${composeDueAt.value}T${composeHasTime.value ? composeTime.value : '23:59'}` : ''
     if (composeRepeat.value !== 'none' && !dueValue) throw new Error('请先设置截止时间')
     await taskMutationReconciler.run(
@@ -1093,6 +1098,7 @@ async function saveSelectedTaskChanges() {
   const repeatValue = selectedDueDate.value ? selectedTaskRepeat.value : 'none'
   const repeatConfig = JSON.parse(JSON.stringify(selectedRepeatConfig.value)) as TaskRepeatConfig
   const afterCompletionDays = selectedAfterCompletionDays.value
+  const afterCompletionUnit = selectedAfterCompletionUnit.value
   const recurrence = selectedTaskRecurrence.value
   selectedRepeatError.value = ''
   try {
@@ -1102,7 +1108,7 @@ async function saveSelectedTaskChanges() {
       selectedTaskRecurrence.value = null
       selectedTaskRepeat.value = 'none'
     } else {
-      const updatedRecurrence = await saveRepeat(taskSaved, repeatValue, repeatConfig, afterCompletionDays, recurrence)
+      const updatedRecurrence = await saveRepeat(taskSaved, repeatValue, repeatConfig, afterCompletionDays, afterCompletionUnit, recurrence)
       if (recurrenceLoadToken !== selectionToken || selectedTask.value?.id !== taskId) return
       selectedTaskRecurrence.value = updatedRecurrence
     }
@@ -1749,7 +1755,7 @@ onUnmounted(() => {
             <div class="task-detail-field"><span class="task-detail-field-label">时间</span><button v-if="selectedDueDate && !selectedDueHasTime" class="task-compose-time-add task-detail-time-control" type="button" @click="addSelectedDueTime">添加时间</button><label v-else-if="selectedDueDate" class="task-compose-time-chip task-detail-time-control"><input ref="selectedDueTimePicker" v-model="selectedDueTime" type="time" aria-label="选择截止时间"><button class="task-compose-time-remove" type="button" aria-label="移除时间" @click.prevent="selectedDueHasTime=false"><X/></button></label><span v-else class="task-detail-time-empty" aria-hidden="true">—</span></div>
           </div>
           <label class="task-detail-field"><span class="task-detail-field-label">重复</span><select v-model="selectedTaskRepeat" class="task-detail-field-input" :disabled="!selectedDueDate"><option value="none">不重复</option><option value="daily">每天</option><option value="weekly">每周</option><option value="monthly">每月</option><option value="yearly">每年</option><option value="after_completion">完成后重复</option><option value="custom">自定义…</option></select><small v-if="!selectedDueDate" class="field-hint">请先设置截止时间，才能开启重复</small></label>
-          <section v-if="selectedTaskRepeat==='after_completion'" class="after-completion-fields"><div>完成后 <input v-model="selectedAfterCompletionDays" type="number" min="1" max="3650" step="1" inputmode="numeric" aria-label="完成后重复天数"> 天重复</div><small>每次完成后，将截止时间顺延对应天数；首版永不结束</small></section>
+          <section v-if="selectedTaskRepeat==='after_completion'" class="after-completion-fields"><div>完成后 <input v-model="selectedAfterCompletionDays" type="number" min="1" max="3650" step="1" inputmode="numeric" aria-label="完成后重复间隔"><select v-model="selectedAfterCompletionUnit" aria-label="完成后重复单位"><option value="days">天</option><option value="months">月</option></select>重复</div><small>每次完成后，将截止日期按所选间隔顺延；月末会自动取目标月最后一天</small></section>
           <section v-if="selectedTaskRepeat==='custom'" class="repeat-custom-fields"><div><span>每隔</span><input v-model.number="selectedRepeatConfig.interval" type="number" min="1"><select v-model="selectedRepeatConfig.frequency"><option value="daily">天</option><option value="weekly">周</option><option value="monthly">月</option><option value="yearly">年</option></select></div><label v-if="selectedRepeatConfig.frequency==='weekly'">重复日期<span class="weekday-picker"><label v-for="day in weekdayOptions" :key="day.value"><input v-model="selectedRepeatConfig.weekdays" type="checkbox" :value="day.value">{{day.label}}</label></span></label><label v-if="selectedRepeatConfig.frequency==='monthly'">每月日期<input v-model="selectedRepeatConfig.monthDays" placeholder="例如 1,15,31" @change="selectedRepeatConfig.monthDays=String(($event.target as HTMLInputElement).value).split(',').map(Number).filter(Boolean)"></label><label>结束方式<select v-model="selectedRepeatConfig.endMode"><option value="never">永不结束</option><option value="date">指定日期</option><option value="count">重复次数</option></select></label><label v-if="selectedRepeatConfig.endMode==='date'">结束日期<input v-model="selectedRepeatConfig.until" type="date"></label><label v-if="selectedRepeatConfig.endMode==='count'">重复次数<input v-model.number="selectedRepeatConfig.count" type="number" min="1"></label></section>
           <small v-if="selectedRepeatError" role="alert" class="field-error">{{selectedRepeatError}}</small>
         </section>
@@ -1788,7 +1794,7 @@ onUnmounted(() => {
             <label v-else-if="composeDueAt" class="task-compose-time-chip"><span>时间</span><input ref="composeTimePicker" v-model="composeTime" type="time" aria-label="选择截止时间"><button class="task-compose-time-remove" type="button" aria-label="移除时间" @click.prevent="composeHasTime=false"><X/></button></label>
           </div>
           <label>重复<select v-model="composeRepeat" :disabled="!composeDueAt"><option value="none">不重复</option><option value="daily">每天</option><option value="weekly">每周</option><option value="monthly">每月</option><option value="yearly">每年</option><option value="after_completion">完成后重复</option><option value="custom">自定义…</option></select><small v-if="!composeDueAt" class="field-hint">请先设置截止时间，才能开启重复</small></label>
-          <section v-if="composeRepeat==='after_completion'" class="after-completion-fields"><div>完成后 <input v-model="composeAfterCompletionDays" type="number" min="1" max="3650" step="1" inputmode="numeric" aria-label="完成后重复天数"> 天重复</div><small>每次完成后，将截止时间顺延对应天数；首版永不结束</small></section>
+          <section v-if="composeRepeat==='after_completion'" class="after-completion-fields"><div>完成后 <input v-model="composeAfterCompletionDays" type="number" min="1" max="3650" step="1" inputmode="numeric" aria-label="完成后重复间隔"><select v-model="composeAfterCompletionUnit" aria-label="完成后重复单位"><option value="days">天</option><option value="months">月</option></select>重复</div><small>每次完成后，将截止日期按所选间隔顺延；月末会自动取目标月最后一天</small></section>
           <small v-if="composeRepeatError" role="alert" class="field-error">{{composeRepeatError}}</small>
           <section v-if="composeRepeat==='custom'" class="repeat-custom-fields"><div><span>每隔</span><input v-model.number="composeRepeatConfig.interval" type="number" min="1"><select v-model="composeRepeatConfig.frequency"><option value="daily">天</option><option value="weekly">周</option><option value="monthly">月</option><option value="yearly">年</option></select></div><label v-if="composeRepeatConfig.frequency==='weekly'">重复日期<span class="weekday-picker"><label v-for="day in weekdayOptions" :key="day.value"><input v-model="composeRepeatConfig.weekdays" type="checkbox" :value="day.value">{{day.label}}</label></span></label><label v-if="composeRepeatConfig.frequency==='monthly'">每月日期<input v-model.number="composeRepeatConfig.monthDays![0]" type="number" min="1" max="31"></label><label>结束方式<select v-model="composeRepeatConfig.endMode"><option value="never">永不结束</option><option value="date">指定日期</option><option value="count">重复次数</option></select></label><label v-if="composeRepeatConfig.endMode==='date'">结束日期<input v-model="composeRepeatConfig.until" type="date"></label><label v-if="composeRepeatConfig.endMode==='count'">重复次数<input v-model.number="composeRepeatConfig.count" type="number" min="1"></label></section>
           <label>备注<textarea v-model="composeDescription" rows="3" placeholder="可选，支持 Markdown"/></label>

frontend/src/lib/task-utils.test.ts

@@ -75,12 +75,14 @@ describe('task utilities', () => {
     expect(() => buildTaskRrule({ frequency: 'daily', interval: 0, weekdays: [], monthDays: [], endMode: 'never', count: 10, until: '' })).toThrow('重复间隔至少为 1')
   })
 
-  it('builds a distinct completion-trigger payload and parses it without RRULE', () => {
-    expect(buildTaskRecurrencePayload('after_completion', { afterCompletionDays: '7' })).toEqual({ trigger_mode: 'after_completion', after_completion_days: 7 })
-    expect(parseTaskRecurrence({ rrule: null, trigger_mode: 'after_completion', after_completion_days: 14 })).toEqual({ option: 'after_completion', afterCompletionDays: 14 })
-    expect(() => buildTaskRecurrencePayload('after_completion', { afterCompletionDays: '1.5' })).toThrow('请输入 1 到 3650 的整数天数')
-    expect(() => buildTaskRecurrencePayload('after_completion', { afterCompletionDays: '0' })).toThrow('请输入 1 到 3650 的整数天数')
-    expect(() => buildTaskRecurrencePayload('after_completion', { afterCompletionDays: '3651' })).toThrow('请输入 1 到 3650 的整数天数')
+  it('builds and parses completion-trigger intervals in days or months', () => {
+    expect(buildTaskRecurrencePayload('after_completion', { afterCompletionDays: '7' })).toEqual({ trigger_mode: 'after_completion', after_completion_days: 7, after_completion_unit: 'days' })
+    expect(buildTaskRecurrencePayload('after_completion', { afterCompletionDays: '2', afterCompletionUnit: 'months' })).toEqual({ trigger_mode: 'after_completion', after_completion_days: 2, after_completion_unit: 'months' })
+    expect(parseTaskRecurrence({ rrule: null, trigger_mode: 'after_completion', after_completion_days: 14 })).toEqual({ option: 'after_completion', afterCompletionDays: 14, afterCompletionUnit: 'days' })
+    expect(parseTaskRecurrence({ rrule: null, trigger_mode: 'after_completion', after_completion_days: 3, after_completion_unit: 'months' })).toEqual({ option: 'after_completion', afterCompletionDays: 3, afterCompletionUnit: 'months' })
+    expect(() => buildTaskRecurrencePayload('after_completion', { afterCompletionDays: '1.5' })).toThrow('请输入 1 到 3650 的整数')
+    expect(() => buildTaskRecurrencePayload('after_completion', { afterCompletionDays: '0' })).toThrow('请输入 1 到 3650 的整数')
+    expect(() => buildTaskRecurrencePayload('after_completion', { afterCompletionDays: '3651' })).toThrow('请输入 1 到 3650 的整数')
   })
 
   it('builds scheduled recurrence payloads separately from completion triggers', () => {

frontend/src/lib/task-utils.ts

@@ -172,15 +172,16 @@ export function parseTaskRrule(rrule = ''): TaskRepeatConfig {
 }
 
 export type TaskRepeatOption = 'none' | 'daily' | 'weekly' | 'monthly' | 'yearly' | 'after_completion' | 'custom'
-export type TaskRecurrenceRecord = { rrule?: string | null; trigger_mode?: 'scheduled' | 'after_completion'; after_completion_days?: number | null }
+export type AfterCompletionUnit = 'days' | 'months'
+export type TaskRecurrenceRecord = { rrule?: string | null; trigger_mode?: 'scheduled' | 'after_completion'; after_completion_days?: number | null; after_completion_unit?: AfterCompletionUnit | null }
 
-export function buildTaskRecurrencePayload(option: TaskRepeatOption, values: { afterCompletionDays: string | number; repeatConfig?: TaskRepeatConfig }) {
+export function buildTaskRecurrencePayload(option: TaskRepeatOption, values: { afterCompletionDays: string | number; afterCompletionUnit?: AfterCompletionUnit; repeatConfig?: TaskRepeatConfig }) {
   if (option === 'none') return {}
   if (option === 'after_completion') {
     const raw = String(values.afterCompletionDays).trim()
     const days = Number(raw)
-    if (!/^\d+$/.test(raw) || !Number.isInteger(days) || days < 1 || days > 3650) throw new Error('请输入 1 到 3650 的整数天数')
-    return { trigger_mode: 'after_completion' as const, after_completion_days: days }
+    if (!/^\d+$/.test(raw) || !Number.isInteger(days) || days < 1 || days > 3650) throw new Error('请输入 1 到 3650 的整数')
+    return { trigger_mode: 'after_completion' as const, after_completion_days: days, after_completion_unit: values.afterCompletionUnit ?? 'days' }
   }
   const rrule = option === 'custom'
     ? buildTaskRrule(values.repeatConfig ?? { frequency: 'daily', interval: 1, endMode: 'never' })
@@ -189,13 +190,13 @@ export function buildTaskRecurrencePayload(option: TaskRepeatOption, values: { a
 }
 
 export function parseTaskRecurrence(recurrence?: TaskRecurrenceRecord | null) {
-  if (!recurrence) return { option: 'none' as TaskRepeatOption, afterCompletionDays: 1 }
+  if (!recurrence) return { option: 'none' as TaskRepeatOption, afterCompletionDays: 1, afterCompletionUnit: 'days' as AfterCompletionUnit }
   if (recurrence.trigger_mode === 'after_completion') {
-    return { option: 'after_completion' as TaskRepeatOption, afterCompletionDays: recurrence.after_completion_days ?? 1 }
+    return { option: 'after_completion' as TaskRepeatOption, afterCompletionDays: recurrence.after_completion_days ?? 1, afterCompletionUnit: recurrence.after_completion_unit ?? 'days' as AfterCompletionUnit }
   }
   const parsed = parseTaskRrule(recurrence.rrule ?? '')
   const simple = parsed.interval === 1 && !parsed.weekdays?.length && !parsed.monthDays?.length && parsed.endMode === 'never'
-  return { option: (simple ? parsed.frequency : 'custom') as TaskRepeatOption, afterCompletionDays: 1 }
+  return { option: (simple ? parsed.frequency : 'custom') as TaskRepeatOption, afterCompletionDays: 1, afterCompletionUnit: 'days' as AfterCompletionUnit }
 }
 
 export function defaultTaskDueAt(now = new Date()) {

frontend/src/style.test.ts

@@ -1370,10 +1370,13 @@ describe('unified floating add interaction', () => {
     expect(app).toContain('<span class="task-detail-field-label">重复</span><select v-model="selectedTaskRepeat"')
     expect(app).toContain('<option value="yearly">每年</option><option value="after_completion">完成后重复</option><option value="custom">自定义…</option>')
     expect(app).toContain('完成后 <input v-model="composeAfterCompletionDays"')
+    expect(app).toContain('v-model="composeAfterCompletionUnit"')
     expect(app).toContain('完成后 <input v-model="selectedAfterCompletionDays"')
-    expect(app).toContain('每次完成后，将截止时间顺延对应天数；首版永不结束')
+    expect(app).toContain('v-model="selectedAfterCompletionUnit"')
+    expect(app).toContain('<option value="days">天</option><option value="months">月</option>')
+    expect(app).toContain('月末会自动取目标月最后一天')
     expect(app).toContain('buildTaskRecurrencePayload(composeRepeat.value')
-    expect(app).toContain('buildTaskRecurrencePayload(value, { afterCompletionDays, repeatConfig: config })')
+    expect(app).toContain('buildTaskRecurrencePayload(value, { afterCompletionDays, afterCompletionUnit, repeatConfig: config })')
     expect(app).toContain("api(`/tasks/${task.id}/recurrence`)")
     const createBlock = app.slice(app.indexOf('async function submitTaskCompose()'), app.indexOf('function toggleSidebar()'))
     expect(createBlock).toContain("api('/tasks',")
@@ -1388,7 +1391,7 @@ describe('unified floating add interaction', () => {
     expect(saveBlock).toContain('if (!taskSaved.due_at) {')
     expect(saveBlock).toContain('selectedTaskRecurrence.value = null')
     expect(saveBlock).toContain("selectedTaskRepeat.value = 'none'")
-    expect(saveBlock).toContain('await saveRepeat(taskSaved, repeatValue, repeatConfig, afterCompletionDays, recurrence)')
+    expect(saveBlock).toContain('await saveRepeat(taskSaved, repeatValue, repeatConfig, afterCompletionDays, afterCompletionUnit, recurrence)')
     const dueRemovalBlock = saveBlock.slice(saveBlock.indexOf('if (!taskSaved.due_at) {'), saveBlock.indexOf('} else {'))
     expect(dueRemovalBlock).not.toContain('saveRepeat(')
     expect(saveBlock).toContain("selectedRepeatError.value = ''")

migrations/versions/0017_after_completion_unit.py

@@ -0,0 +1,29 @@
+"""add after_completion unit
+
+Revision ID: 0021_after_completion_unit
+Revises: 0020_calendar_subscriptions
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+revision = "0021_after_completion_unit"
+down_revision = "0020_calendar_subscriptions"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    with op.batch_alter_table("recurrence_templates") as batch_op:
+        batch_op.add_column(
+            sa.Column("after_completion_unit", sa.String(length=8), nullable=True)
+        )
+    op.execute(
+        "UPDATE recurrence_templates SET after_completion_unit = 'days' "
+        "WHERE trigger_mode = 'after_completion'"
+    )
+
+
+def downgrade() -> None:
+    with op.batch_alter_table("recurrence_templates") as batch_op:
+        batch_op.drop_column("after_completion_unit")

tests/test_after_completion_recurrence.py

@@ -48,7 +48,7 @@ def test_dst_gap_rolls_forward_and_ambiguous_time_uses_first_fold():
         due_has_time=True,
     )
     gap_due = recurrence_service._after_completion_due(
-        gap_task, datetime(2026, 3, 7, 15, tzinfo=UTC), 1, user
+        gap_task, datetime(2026, 3, 7, 15, tzinfo=UTC), 1, "days", user
     )
     assert gap_due == datetime(2026, 3, 8, 7, 30, tzinfo=UTC)  # local 03:30 after gap
 
@@ -60,7 +60,7 @@ def test_dst_gap_rolls_forward_and_ambiguous_time_uses_first_fold():
         due_has_time=True,
     )
     fold_due = recurrence_service._after_completion_due(
-        fold_task, datetime(2026, 10, 31, 15, tzinfo=UTC), 1, user
+        fold_task, datetime(2026, 10, 31, 15, tzinfo=UTC), 1, "days", user
     )
     assert fold_due == datetime(2026, 11, 1, 5, 30, tzinfo=UTC)  # first 01:30, fold=0
 
@@ -89,6 +89,30 @@ def test_user_timezone_is_the_calendar_contract_for_after_completion(client, mon
     assert datetime.fromisoformat(completed.json()["due_at"]) == datetime(2026, 3, 9, 9, 30, tzinfo=UTC)
 
 
+def test_month_interval_uses_calendar_month_clamping(client, monkeypatch):
+    inbox = boot(client)
+    task = create_after_completion_task(
+        client,
+        inbox,
+        due_at="2026-01-31T01:30:00Z",
+        after_completion_days=1,
+        after_completion_unit="months",
+    ).json()
+    monkeypatch.setattr(
+        "backend.recurrence_service.utcnow",
+        lambda: datetime(2026, 1, 30, 16, 30, tzinfo=UTC),  # 2026-01-31 00:30 Asia/Shanghai
+    )
+
+    completed = client.patch(
+        f"/api/v1/tasks/{task['id']}", json={"completed": True, "version": task["version"]}
+    )
+
+    assert completed.status_code == 200
+    assert datetime.fromisoformat(completed.json()["due_at"]) == datetime(2026, 2, 28, 1, 30, tzinfo=UTC)
+    recurrence = client.get(f"/api/v1/tasks/{task['id']}/recurrence").json()
+    assert recurrence["after_completion_unit"] == "months"
+
+
 def test_atomic_task_create_and_read_after_completion_recurrence(client):
     inbox = boot(client)
 
@@ -105,6 +129,7 @@ def test_atomic_task_create_and_read_after_completion_recurrence(client):
         "ends_at": None,
         "trigger_mode": "after_completion",
         "after_completion_days": 2,
+        "after_completion_unit": "days",
         "last_completed_at": None,
     }
 
@@ -122,6 +147,8 @@ def test_after_completion_configuration_validation(client):
         {"title": "零天", "list_id": inbox["id"], "due_at": "2026-03-08T01:30:00Z", "trigger_mode": "after_completion", "after_completion_days": 0},
         {"title": "太长", "list_id": inbox["id"], "due_at": "2026-03-08T01:30:00Z", "trigger_mode": "after_completion", "after_completion_days": 3651},
         {"title": "子任务", "list_id": inbox["id"], "parent_id": child["id"], "due_at": "2026-03-08T01:30:00Z", "trigger_mode": "after_completion", "after_completion_days": 1},
+        {"title": "只有单位", "list_id": inbox["id"], "due_at": "2026-03-08T01:30:00Z", "after_completion_unit": "months"},
+        {"title": "定期带月份", "list_id": inbox["id"], "due_at": "2026-03-08T01:30:00Z", "trigger_mode": "scheduled", "rrule": "FREQ=DAILY", "after_completion_unit": "months"},
     ]
     for payload in invalid_payloads:
         assert client.post("/api/v1/tasks", json=payload).status_code in {400, 422}

tests/test_backup_v2.py

@@ -200,6 +200,36 @@ def test_merge_same_backup_is_idempotent_via_import_ledger(client):
     assert asyncio.run(counts()) == (1, 1)
 
 
+def test_legacy_backup_without_completion_unit_is_idempotent(client):
+    inbox = boot(client)
+    client.post(
+        "/api/v1/tasks",
+        json={
+            "title": "旧版完成后重复",
+            "list_id": inbox["id"],
+            "due_at": "2026-03-08T01:30:00Z",
+            "trigger_mode": "after_completion",
+            "after_completion_days": 2,
+        },
+    )
+    content = client.get("/api/v1/backup/export.zip").content
+    recurrences = _archive_rows(content, "recurrences")
+    for recurrence in recurrences:
+        recurrence.pop("after_completion_unit", None)
+    legacy_content = _replace_entities(content, {"recurrences": recurrences})
+
+    first_token = _preflight(client, legacy_content).json()["preflight_token"]
+    assert client.post(
+        "/api/v1/backup/restore", json={"preflight_token": first_token, "mode": "merge"}
+    ).status_code == 200
+    second_token = _preflight(client, legacy_content).json()["preflight_token"]
+    second = client.post(
+        "/api/v1/backup/restore", json={"preflight_token": second_token, "mode": "merge"}
+    )
+    assert second.status_code == 200
+    assert second.json()["already_imported"] is True
+
+
 def test_invalid_zip_variants_are_rejected_before_any_write(client):
     inbox = boot(client)
     before = len(client.get("/api/v1/tasks", params={"list_id": inbox["id"]}).json()["items"])