diff --git a/frontend/src/App.vue b/frontend/src/App.vue
index 7e72eba..a32676b 100644
--- a/frontend/src/App.vue
+++ b/frontend/src/App.vue
@@ -5,8 +5,8 @@ import {
   GripVertical, Inbox, ListChecks, ListTodo, Menu, Pencil, Plus, Search,
   Settings, Trash2, X, Repeat2,
 } from 'lucide-vue-next'
-import { buildTaskRrule, filterTasks, fromDateTimeLocal, groupTaskTree, moveItemWithinScope, parseTaskRrule, renderMarkdown, toDateTimeLocal, type TaskRepeatConfig } from './lib/task-utils'
-import { defaultView, isTaskView, nextTotalAfterLocalTaskAdd, quickTaskFields, shouldToggleRowSwipe, writeCountdownCache } from './lib/mvp-utils'
+import { buildTaskRrule, defaultTaskDueAt, filterTasks, fromDateTimeLocal, groupTaskTree, moveItemWithinScope, parseTaskRrule, renderMarkdown, toDateTimeLocal, type TaskRepeatConfig } from './lib/task-utils'
+import { defaultView, isTaskView, nextTotalAfterLocalTaskAdd, shouldToggleRowSwipe, writeCountdownCache } from './lib/mvp-utils'
 import { csrfHeader } from './lib/csrf'
 import MvpPanel from './MvpPanel.vue'
 import CountdownPanel from './CountdownPanel.vue'
@@ -80,7 +80,7 @@ function openTaskCompose() {
   const inboxId = lists.value.find((item) => item.is_inbox)?.id || activeList.value
   composeTitle.value = ''
   composeListId.value = activeView.value === 'tasks' && activeList.value ? activeList.value : inboxId
-  composeDueAt.value = activeView.value === 'today' ? toDateTimeLocal(quickTaskFields('today', activeList.value, inboxId).due_at ?? null) : ''
+  composeDueAt.value = defaultTaskDueAt()
   composePriority.value = 0
   composeDescription.value = ''
   composeRepeat.value = 'none'
diff --git a/frontend/src/lib/task-utils.test.ts b/frontend/src/lib/task-utils.test.ts
index cd07e6f..8075609 100644
--- a/frontend/src/lib/task-utils.test.ts
+++ b/frontend/src/lib/task-utils.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest'
-import { buildTaskRrule, filterTasks, groupTaskTree, moveItemWithinScope, parseTaskRrule, renderMarkdown, toDateTimeLocal } from './task-utils'
+import { buildTaskRrule, defaultTaskDueAt, filterTasks, groupTaskTree, moveItemWithinScope, parseTaskRrule, renderMarkdown, toDateTimeLocal } from './task-utils'
 
 type SearchTask = {
   id: string
@@ -63,6 +63,11 @@ describe('task utilities', () => {
     expect(filterTasks(searchable, '工作').map((task) => task.id)).toEqual(['4'])
   })
 
+  it('defaults new tasks to today at noon in local time', () => {
+    const due = defaultTaskDueAt(new Date(2026, 8, 8, 21, 30))
+    expect(due).toBe('2026-09-08T12:00')
+  })
+
   it('formats API dates in local wall-clock time', () => {
     const original = process.env.TZ
     process.env.TZ = 'Asia/Shanghai'
diff --git a/frontend/src/lib/task-utils.ts b/frontend/src/lib/task-utils.ts
index f7ee3b3..774f5d2 100644
--- a/frontend/src/lib/task-utils.ts
+++ b/frontend/src/lib/task-utils.ts
@@ -144,6 +144,13 @@ export function parseTaskRrule(rrule = ''): TaskRepeatConfig {
   }
 }
 
+export function defaultTaskDueAt(now = new Date()) {
+  const year = now.getFullYear()
+  const month = `${now.getMonth() + 1}`.padStart(2, '0')
+  const day = `${now.getDate()}`.padStart(2, '0')
+  return `${year}-${month}-${day}T12:00`
+}
+
 export function toDateTimeLocal(value: string | null | undefined) {
   if (!value) return ''
   const date = new Date(value)
diff --git a/frontend/src/style.test.ts b/frontend/src/style.test.ts
index b866cdc..60c1b35 100644
--- a/frontend/src/style.test.ts
+++ b/frontend/src/style.test.ts
@@ -183,6 +183,11 @@ describe('mobile touch targets', () => {
 })
 
 describe('unified floating add interaction', () => {
+  it('defaults every new-task composer to today', () => {
+    expect(app).toContain('composeDueAt.value = defaultTaskDueAt()')
+    expect(app).not.toContain("activeView.value === 'today' ? toDateTimeLocal(quickTaskFields")
+  })
+
   it('lets task create and detail forms configure a repeat rule', () => {
     expect(app).toContain('const composeRepeat = ref')
     expect(app).toContain('const selectedTaskRepeat = ref')