diff --git a/client/src/components/common/LocalizedDatePicker.vue b/client/src/components/common/LocalizedDatePicker.vue
new file mode 100644
index 0000000..b00e863
--- /dev/null
+++ b/client/src/components/common/LocalizedDatePicker.vue
@@ -0,0 +1,124 @@
+<template>
+  <DatePicker
+    v-model="dateModel"
+    :input-id="inputId"
+    class="localized-date-picker"
+    date-format="yy-mm-dd"
+    :placeholder="placeholder"
+    :input-class="inputClass"
+    :pt="datePickerPt"
+    :invalid="invalid"
+    :disabled="disabled"
+    :required="required"
+    show-icon
+    icon-display="input"
+    append-to="body"
+    :panel-class="panelClass"
+  />
+</template>
+
+<script setup lang="ts">
+import DatePicker from 'primevue/datepicker'
+import { usePrimeVue } from 'primevue/config'
+import { computed, watch } from 'vue'
+import { useI18n } from 'vue-i18n'
+
+import {
+  formatDatePickerValue,
+  normalizeDatePickerLocale,
+  parseDatePickerValue,
+  primeVueDatePickerLocales,
+} from '@/utils/localizedDatePicker'
+
+const props = withDefaults(defineProps<{
+  modelValue: string
+  inputId: string
+  name?: string
+  testId: string
+  panelTestId?: string
+  placeholder?: string
+  inputClass?: string | Record<string, boolean>
+  invalid?: boolean
+  describedBy?: string
+  disabled?: boolean
+  required?: boolean
+  panelClass?: string
+}>(), {
+  name: undefined,
+  panelTestId: undefined,
+  placeholder: '',
+  inputClass: undefined,
+  invalid: false,
+  describedBy: undefined,
+  disabled: false,
+  required: false,
+  panelClass: 'localized-date-picker-panel',
+})
+
+const emit = defineEmits<{
+  'update:modelValue': [value: string]
+}>()
+
+const { locale } = useI18n()
+const primeVue = usePrimeVue()
+
+const dateModel = computed<Date | null>({
+  get: () => parseDatePickerValue(props.modelValue),
+  set: (value) => {
+    emit('update:modelValue', formatDatePickerValue(value))
+  },
+})
+
+const datePickerPt = computed(() => ({
+  pcInputText: {
+    root: {
+      name: props.name,
+      'data-testid': props.testId,
+      lang: locale.value,
+      'aria-invalid': props.invalid ? 'true' : undefined,
+      'aria-describedby': props.describedBy,
+    },
+  },
+  panel: {
+    lang: locale.value,
+    'data-testid': props.panelTestId ?? `${props.testId}-panel`,
+  },
+}))
+
+watch(
+  locale,
+  (nextLocale) => {
+    const supportedLocale = normalizeDatePickerLocale(nextLocale)
+    primeVue.config.locale = {
+      ...(primeVue.config.locale ?? primeVueDatePickerLocales['en-US']),
+      ...primeVueDatePickerLocales[supportedLocale],
+    }
+  },
+  { immediate: true },
+)
+</script>
+
+<style scoped>
+.localized-date-picker {
+  display: block;
+  width: 100%;
+}
+
+.localized-date-picker :deep(.p-inputtext) {
+  width: 100%;
+  padding-right: 40px;
+}
+
+.localized-date-picker :deep(.p-datepicker-input-icon-container) {
+  right: 12px;
+  color: var(--th-color-navy-950);
+}
+</style>
+
+<style>
+.localized-date-picker-panel {
+  z-index: 1200;
+  color: var(--th-color-navy-950);
+  font-family: inherit;
+}
+</style>
diff --git a/client/src/components/reservation/ReservationV4TaskCardFieldRenderer.vue b/client/src/components/reservation/ReservationV4TaskCardFieldRenderer.vue
index 8ef772b..f665dd6 100644
--- a/client/src/components/reservation/ReservationV4TaskCardFieldRenderer.vue
+++ b/client/src/components/reservation/ReservationV4TaskCardFieldRenderer.vue
@@ -31,15 +31,16 @@
         </option>
       </select>
 
-      <input
+      <LocalizedDatePicker
         v-else-if="isEditable(field) && isDateField(field)"
-        class="v4-field__control"
-        type="date"
+        :model-value="dateFieldValue(field)"
+        :input-id="dateFieldInputId(field)"
         :name="fieldKey(field)"
-        :aria-invalid="fieldError(field) ? 'true' : 'false'"
-        :value="fieldValue(field)"
-        @input="updateField(field, $event)"
-      >
+        :test-id="fieldKey(field)"
+        :placeholder="t('taskV4.field.datePlaceholder')"
+        :invalid="Boolean(fieldError(field))"
+        @update:model-value="updateFieldValue(field, $event)"
+      />
 
       <input
         v-else-if="isEditable(field) && isCheckboxField(field)"
@@ -120,6 +121,7 @@
 import { computed, reactive, watch } from 'vue'
 import { useI18n } from 'vue-i18n'
 
+import LocalizedDatePicker from '@/components/common/LocalizedDatePicker.vue'
 import {
   fetchReservationV4AccountLookups,
   fetchReservationV4RateCodeLookups,
@@ -225,6 +227,10 @@ function fieldKey(field: ReservationV4TaskCardFieldResult): string {
   return reservationV4FieldKey(field)
 }
 
+function dateFieldInputId(field: ReservationV4TaskCardFieldResult): string {
+  return `v4-date-${fieldKey(field).replace(/[^a-zA-Z0-9_-]/g, '-')}`
+}
+
 function isEditable(field: ReservationV4TaskCardFieldResult): boolean {
   const key = reservationV4FieldKey(field)
   return !props.readOnly &&
@@ -296,6 +302,11 @@ function fieldValue(field: ReservationV4TaskCardFieldResult): string | number {
   return stringifyV4Value(value)
 }
 
+function dateFieldValue(field: ReservationV4TaskCardFieldResult): string {
+  const value = readV4FieldValue(field, props.modelValue)
+  return typeof value === 'string' ? value : stringifyV4Value(value)
+}
+
 function staticFieldValue(field: ReservationV4TaskCardFieldResult): string {
   const value = fieldValue(field)
   const matchedOption = fieldOptions(field).find((option) => option.value === value)
@@ -309,10 +320,14 @@ function checkboxValue(field: ReservationV4TaskCardFieldResult): boolean {
 
 function updateField(field: ReservationV4TaskCardFieldResult, event: Event): void {
   const target = event.target as HTMLInputElement | HTMLSelectElement | HTMLTextAreaElement
+  updateFieldValue(field, target.value)
+}
+
+function updateFieldValue(field: ReservationV4TaskCardFieldResult, value: string): void {
   delete invalidLookupValues[reservationV4FieldKey(field)]
   emit('update:modelValue', {
     ...props.modelValue,
-    [reservationV4FieldKey(field)]: target.value,
+    [reservationV4FieldKey(field)]: value,
   })
 }
 
diff --git a/client/src/i18n/locales/en-US.ts b/client/src/i18n/locales/en-US.ts
index 345ec69..2a98e4e 100644
--- a/client/src/i18n/locales/en-US.ts
+++ b/client/src/i18n/locales/en-US.ts
@@ -698,6 +698,7 @@ export default {
       empty: 'Empty',
       hidden: 'Sensitive content hidden',
       selectPlaceholder: 'Select',
+      datePlaceholder: 'yyyy-mm-dd',
     },
     error: {
       loadFailed: 'Failed to load the reservation item handling page.',
diff --git a/client/src/i18n/locales/th-TH.ts b/client/src/i18n/locales/th-TH.ts
index 8f05cbb..f27087c 100644
--- a/client/src/i18n/locales/th-TH.ts
+++ b/client/src/i18n/locales/th-TH.ts
@@ -698,6 +698,7 @@ export default {
       empty: 'ยังไม่กรอก',
       hidden: 'ซ่อนข้อมูลที่อ่อนไหวแล้ว',
       selectPlaceholder: 'เลือก',
+      datePlaceholder: 'yyyy-mm-dd',
     },
     error: {
       loadFailed: 'โหลดหน้าจัดการรายการจองไม่สำเร็จ',
diff --git a/client/src/i18n/locales/zh-CN.ts b/client/src/i18n/locales/zh-CN.ts
index 73b2ea3..19a2ece 100644
--- a/client/src/i18n/locales/zh-CN.ts
+++ b/client/src/i18n/locales/zh-CN.ts
@@ -698,6 +698,7 @@ export default {
       empty: '未填写',
       hidden: '敏感内容已隐藏',
       selectPlaceholder: '请选择',
+      datePlaceholder: '年-月-日',
     },
     error: {
       loadFailed: '订单事项办理页加载失败。',
diff --git a/client/src/tests/reservationV4Views.spec.ts b/client/src/tests/reservationV4Views.spec.ts
index b1d3170..9ef2b36 100644
--- a/client/src/tests/reservationV4Views.spec.ts
+++ b/client/src/tests/reservationV4Views.spec.ts
@@ -1,5 +1,6 @@
 import { flushPromises, mount } from '@vue/test-utils'
 import { createPinia, setActivePinia } from 'pinia'
+import PrimeVue from 'primevue/config'
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 import { createI18n } from 'vue-i18n'
 import { createMemoryHistory, createRouter } from 'vue-router'
@@ -40,6 +41,20 @@ const service = await import('@/services/reservationService')
 describe('reservation V4 pages', () => {
   beforeEach(() => {
     sessionStorage.clear()
+    Object.defineProperty(window, 'matchMedia', {
+      configurable: true,
+      writable: true,
+      value: vi.fn().mockImplementation((query: string) => ({
+        matches: false,
+        media: query,
+        onchange: null,
+        addListener: vi.fn(),
+        removeListener: vi.fn(),
+        addEventListener: vi.fn(),
+        removeEventListener: vi.fn(),
+        dispatchEvent: vi.fn(),
+      })),
+    })
     vi.mocked(service.ackReservationV4SourceNotification).mockReset()
     vi.mocked(service.confirmReservationV4OrderTaskCard).mockReset()
     vi.mocked(service.fetchReservationV4AccountLookups).mockReset()
@@ -780,8 +795,10 @@ describe('reservation V4 pages', () => {
     expect((breakfast.element as HTMLInputElement).disabled).toBe(true)
     expect((roomCard.find('input[name="/room_information/final_values/group_block_name"]').element as HTMLInputElement).value)
       .toBe('GRP-V4-RI-GROUP-001')
+    expect(roomCard.find('input[name="/room_information/final_values/arrival_date"]').attributes('type')).toBe('text')
     expect((roomCard.find('input[name="/room_information/final_values/arrival_date"]').element as HTMLInputElement).value)
       .toBe('2026-07-26')
+    expect(roomCard.find('input[name="/room_information/final_values/departure_date"]').attributes('type')).toBe('text')
     expect((roomCard.find('input[name="/room_information/final_values/departure_date"]').element as HTMLInputElement).value)
       .toBe('2026-07-29')
 
@@ -1405,7 +1422,7 @@ async function mountWithPlugins(component: object, initialPath: string) {
 
   return mount(component, {
     global: {
-      plugins: [pinia, i18n, router],
+      plugins: [pinia, i18n, router, PrimeVue],
       stubs: {
         RouterLink: {
           template: '<a><slot /></a>',
diff --git a/client/src/utils/localizedDatePicker.ts b/client/src/utils/localizedDatePicker.ts
new file mode 100644
index 0000000..ba72c1f
--- /dev/null
+++ b/client/src/utils/localizedDatePicker.ts
@@ -0,0 +1,130 @@
+import type { PrimeVueLocaleOptions } from 'primevue/config'
+
+export type SupportedDatePickerLocale = 'zh-CN' | 'en-US' | 'th-TH'
+
+export type LocalizedDatePickerLocaleOptions = Pick<
+  PrimeVueLocaleOptions,
+  'fileSizeTypes' | 'dayNames' | 'dayNamesShort' | 'dayNamesMin' | 'monthNames' | 'monthNamesShort'
+> &
+  Partial<PrimeVueLocaleOptions>
+
+export const primeVueDatePickerLocales: Record<SupportedDatePickerLocale, LocalizedDatePickerLocaleOptions> = {
+  'zh-CN': {
+    fileSizeTypes: ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'],
+    dayNames: ['星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六'],
+    dayNamesShort: ['周日', '周一', '周二', '周三', '周四', '周五', '周六'],
+    dayNamesMin: ['日', '一', '二', '三', '四', '五', '六'],
+    monthNames: ['一月', '二月', '三月', '四月', '五月', '六月', '七月', '八月', '九月', '十月', '十一月', '十二月'],
+    monthNamesShort: ['1月', '2月', '3月', '4月', '5月', '6月', '7月', '8月', '9月', '10月', '11月', '12月'],
+    chooseDate: '选择日期',
+    chooseMonth: '选择月份',
+    chooseYear: '选择年份',
+    prevMonth: '上个月',
+    nextMonth: '下个月',
+    prevYear: '上一年',
+    nextYear: '下一年',
+    today: '今天',
+    clear: '清除',
+    firstDayOfWeek: 1,
+    showMonthAfterYear: true,
+    dateFormat: 'yy-mm-dd',
+  },
+  'en-US': {
+    fileSizeTypes: ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'],
+    dayNames: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'],
+    dayNamesShort: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
+    dayNamesMin: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
+    monthNames: [
+      'January',
+      'February',
+      'March',
+      'April',
+      'May',
+      'June',
+      'July',
+      'August',
+      'September',
+      'October',
+      'November',
+      'December',
+    ],
+    monthNamesShort: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
+    chooseDate: 'Choose date',
+    chooseMonth: 'Choose month',
+    chooseYear: 'Choose year',
+    prevMonth: 'Previous month',
+    nextMonth: 'Next month',
+    prevYear: 'Previous year',
+    nextYear: 'Next year',
+    today: 'Today',
+    clear: 'Clear',
+    firstDayOfWeek: 0,
+    showMonthAfterYear: false,
+    dateFormat: 'yy-mm-dd',
+  },
+  'th-TH': {
+    fileSizeTypes: ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'],
+    dayNames: ['วันอาทิตย์', 'วันจันทร์', 'วันอังคาร', 'วันพุธ', 'วันพฤหัสบดี', 'วันศุกร์', 'วันเสาร์'],
+    dayNamesShort: ['อา.', 'จ.', 'อ.', 'พ.', 'พฤ.', 'ศ.', 'ส.'],
+    dayNamesMin: ['อา.', 'จ.', 'อ.', 'พ.', 'พฤ.', 'ศ.', 'ส.'],
+    monthNames: [
+      'มกราคม',
+      'กุมภาพันธ์',
+      'มีนาคม',
+      'เมษายน',
+      'พฤษภาคม',
+      'มิถุนายน',
+      'กรกฎาคม',
+      'สิงหาคม',
+      'กันยายน',
+      'ตุลาคม',
+      'พฤศจิกายน',
+      'ธันวาคม',
+    ],
+    monthNamesShort: ['ม.ค.', 'ก.พ.', 'มี.ค.', 'เม.ย.', 'พ.ค.', 'มิ.ย.', 'ก.ค.', 'ส.ค.', 'ก.ย.', 'ต.ค.', 'พ.ย.', 'ธ.ค.'],
+    chooseDate: 'เลือกวันที่',
+    chooseMonth: 'เลือกเดือน',
+    chooseYear: 'เลือกปี',
+    prevMonth: 'เดือนก่อนหน้า',
+    nextMonth: 'เดือนถัดไป',
+    prevYear: 'ปีก่อนหน้า',
+    nextYear: 'ปีถัดไป',
+    today: 'วันนี้',
+    clear: 'ล้าง',
+    firstDayOfWeek: 1,
+    showMonthAfterYear: false,
+    dateFormat: 'yy-mm-dd',
+  },
+}
+
+export function normalizeDatePickerLocale(nextLocale: string): SupportedDatePickerLocale {
+  if (nextLocale === 'en-US' || nextLocale === 'th-TH') {
+    return nextLocale
+  }
+  return 'zh-CN'
+}
+
+export function parseDatePickerValue(value: string): Date | null {
+  const match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(value)
+  if (!match) {
+    return null
+  }
+  const year = Number(match[1])
+  const month = Number(match[2])
+  const day = Number(match[3])
+  const date = new Date(year, month - 1, day)
+  if (date.getFullYear() !== year || date.getMonth() !== month - 1 || date.getDate() !== day) {
+    return null
+  }
+  return date
+}
+
+export function formatDatePickerValue(value: Date | null | undefined): string {
+  if (!(value instanceof Date) || Number.isNaN(value.getTime())) {
+    return ''
+  }
+  const year = value.getFullYear()
+  const month = String(value.getMonth() + 1).padStart(2, '0')
+  const day = String(value.getDate()).padStart(2, '0')
+  return `${year}-${month}-${day}`
+}
diff --git a/client/src/views/reservation/ReservationManualInvoiceView.vue b/client/src/views/reservation/ReservationManualInvoiceView.vue
index 8578657..02f3104 100644
--- a/client/src/views/reservation/ReservationManualInvoiceView.vue
+++ b/client/src/views/reservation/ReservationManualInvoiceView.vue
@@ -201,20 +201,14 @@
                 >Booking Date</label>
               </div>
               <div class="date-control">
-                <DatePicker
-                  v-model="documentBookingDateModel"
+                <LocalizedDatePicker
+                  v-model="form.document.booking_date"
                   input-id="invoice-booking-date"
-                  class="localized-date-picker"
-                  data-testid="document-booking-date-picker"
-                  date-format="yy-mm-dd"
+                  test-id="document-booking-date"
                   :placeholder="t('manualInvoice.datePlaceholder')"
                   :input-class="validationClass('booking-date')"
-                  :pt="datePickerPt('document-booking-date', 'booking-date')"
                   :invalid="Boolean(fieldError('booking-date'))"
-                  show-icon
-                  icon-display="input"
-                  append-to="body"
-                  panel-class="manual-invoice-datepicker-panel"
+                  :described-by="fieldError('booking-date') ? fieldErrorId('booking-date') : undefined"
                   required
                   @update:model-value="markDocumentDatesEdited"
                 />
@@ -274,20 +268,14 @@
                 >Arrival Date</label>
               </div>
               <div class="date-control">
-                <DatePicker
-                  v-model="bookingArrivalDateModel"
+                <LocalizedDatePicker
+                  v-model="form.booking.arrival_date"
                   input-id="invoice-arrival-date"
-                  class="localized-date-picker"
-                  data-testid="booking-arrival-date-picker"
-                  date-format="yy-mm-dd"
+                  test-id="booking-arrival-date"
                   :placeholder="t('manualInvoice.datePlaceholder')"
                   :input-class="validationClass('arrival-date')"
-                  :pt="datePickerPt('booking-arrival-date', 'arrival-date')"
                   :invalid="Boolean(fieldError('arrival-date'))"
-                  show-icon
-                  icon-display="input"
-                  append-to="body"
-                  panel-class="manual-invoice-datepicker-panel"
+                  :described-by="fieldError('arrival-date') ? fieldErrorId('arrival-date') : undefined"
                   required
                 />
               </div>
@@ -309,20 +297,14 @@
                 >Departure Date</label>
               </div>
               <div class="date-control">
-                <DatePicker
-                  v-model="bookingDepartureDateModel"
+                <LocalizedDatePicker
+                  v-model="form.booking.departure_date"
                   input-id="invoice-departure-date"
-                  class="localized-date-picker"
-                  data-testid="booking-departure-date-picker"
-                  date-format="yy-mm-dd"
+                  test-id="booking-departure-date"
                   :placeholder="t('manualInvoice.datePlaceholder')"
                   :input-class="validationClass('departure-date')"
-                  :pt="datePickerPt('booking-departure-date', 'departure-date')"
                   :invalid="Boolean(fieldError('departure-date'))"
-                  show-icon
-                  icon-display="input"
-                  append-to="body"
-                  panel-class="manual-invoice-datepicker-panel"
+                  :described-by="fieldError('departure-date') ? fieldErrorId('departure-date') : undefined"
                   required
                 />
               </div>
@@ -344,20 +326,14 @@
                 >Due Date</label>
               </div>
               <div class="date-control">
-                <DatePicker
-                  v-model="documentDueDateModel"
+                <LocalizedDatePicker
+                  v-model="form.document.due_date"
                   input-id="invoice-due-date"
-                  class="localized-date-picker"
-                  data-testid="document-due-date-picker"
-                  date-format="yy-mm-dd"
+                  test-id="document-due-date"
                   :placeholder="t('manualInvoice.datePlaceholder')"
                   :input-class="validationClass('due-date')"
-                  :pt="datePickerPt('document-due-date', 'due-date')"
                   :invalid="Boolean(fieldError('due-date'))"
-                  show-icon
-                  icon-display="input"
-                  append-to="body"
-                  panel-class="manual-invoice-datepicker-panel"
+                  :described-by="fieldError('due-date') ? fieldErrorId('due-date') : undefined"
                   required
                   @update:model-value="markDocumentDatesEdited"
                 />
@@ -812,11 +788,10 @@
 </template>
 
 <script setup lang="ts">
-import DatePicker from 'primevue/datepicker'
-import { usePrimeVue, type PrimeVueLocaleOptions } from 'primevue/config'
 import { computed, reactive, ref, watch } from 'vue'
 import { useI18n } from 'vue-i18n'
 
+import LocalizedDatePicker from '@/components/common/LocalizedDatePicker.vue'
 import { reservationTimeZone } from '@/config/reservationConfig'
 import { ApiError } from '@/services/httpClient'
 import { generateManualReservationInvoice } from '@/services/reservationService'
@@ -833,13 +808,6 @@ const MANUAL_SELECTION = 'MANUAL'
 const VAT_RATE = 0.07
 const previewCurrency = 'THB'
 
-type ManualInvoiceDateLocale = 'zh-CN' | 'en-US' | 'th-TH'
-type ManualInvoiceDatePickerLocale = Pick<
-  PrimeVueLocaleOptions,
-  'fileSizeTypes' | 'dayNames' | 'dayNamesShort' | 'dayNamesMin' | 'monthNames' | 'monthNamesShort'
-> &
-  Partial<PrimeVueLocaleOptions>
-
 interface RecipientContactSeed {
   contact_id: string
   attention: string
@@ -956,7 +924,6 @@ const recipientCompanies: RecipientCompanySeed[] = [
 ]
 
 const { t, te, locale } = useI18n()
-const primeVue = usePrimeVue()
 const authStore = useAuthStore()
 let nextChargeId = 1
 const defaultDocumentDates = createDefaultDocumentDates(resolveHotelTimeZone())
@@ -1005,122 +972,6 @@ const primaryCharge = computed<ChargeForm>(() => form.charges[0] as ChargeForm)
 const sourceGroupName = computed(() => form.booking.group_name.trim() || '未填写')
 const downloadMessage = computed(() => (downloadMessageKey.value ? t(downloadMessageKey.value) : ''))
 const fieldErrors = computed<FieldErrorMap>(() => (validationAttempted.value ? collectFieldErrors() : {}))
-const documentBookingDateModel = createDatePickerModel(
-  () => form.document.booking_date,
-  (value) => {
-    form.document.booking_date = value
-    markDocumentDatesEdited()
-  },
-)
-const documentDueDateModel = createDatePickerModel(
-  () => form.document.due_date,
-  (value) => {
-    form.document.due_date = value
-    markDocumentDatesEdited()
-  },
-)
-const bookingArrivalDateModel = createDatePickerModel(
-  () => form.booking.arrival_date,
-  (value) => {
-    form.booking.arrival_date = value
-  },
-)
-const bookingDepartureDateModel = createDatePickerModel(
-  () => form.booking.departure_date,
-  (value) => {
-    form.booking.departure_date = value
-  },
-)
-
-const primeVueDatePickerLocales: Record<ManualInvoiceDateLocale, ManualInvoiceDatePickerLocale> = {
-  'zh-CN': {
-    fileSizeTypes: ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'],
-    dayNames: ['星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六'],
-    dayNamesShort: ['周日', '周一', '周二', '周三', '周四', '周五', '周六'],
-    dayNamesMin: ['日', '一', '二', '三', '四', '五', '六'],
-    monthNames: ['一月', '二月', '三月', '四月', '五月', '六月', '七月', '八月', '九月', '十月', '十一月', '十二月'],
-    monthNamesShort: ['1月', '2月', '3月', '4月', '5月', '6月', '7月', '8月', '9月', '10月', '11月', '12月'],
-    chooseDate: '选择日期',
-    chooseMonth: '选择月份',
-    chooseYear: '选择年份',
-    prevMonth: '上个月',
-    nextMonth: '下个月',
-    prevYear: '上一年',
-    nextYear: '下一年',
-    today: '今天',
-    clear: '清除',
-    firstDayOfWeek: 1,
-    showMonthAfterYear: true,
-    dateFormat: 'yy-mm-dd',
-  },
-  'en-US': {
-    fileSizeTypes: ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'],
-    dayNames: ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'],
-    dayNamesShort: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
-    dayNamesMin: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'],
-    monthNames: [
-      'January',
-      'February',
-      'March',
-      'April',
-      'May',
-      'June',
-      'July',
-      'August',
-      'September',
-      'October',
-      'November',
-      'December',
-    ],
-    monthNamesShort: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
-    chooseDate: 'Choose date',
-    chooseMonth: 'Choose month',
-    chooseYear: 'Choose year',
-    prevMonth: 'Previous month',
-    nextMonth: 'Next month',
-    prevYear: 'Previous year',
-    nextYear: 'Next year',
-    today: 'Today',
-    clear: 'Clear',
-    firstDayOfWeek: 0,
-    showMonthAfterYear: false,
-    dateFormat: 'yy-mm-dd',
-  },
-  'th-TH': {
-    fileSizeTypes: ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'],
-    dayNames: ['วันอาทิตย์', 'วันจันทร์', 'วันอังคาร', 'วันพุธ', 'วันพฤหัสบดี', 'วันศุกร์', 'วันเสาร์'],
-    dayNamesShort: ['อา.', 'จ.', 'อ.', 'พ.', 'พฤ.', 'ศ.', 'ส.'],
-    dayNamesMin: ['อา.', 'จ.', 'อ.', 'พ.', 'พฤ.', 'ศ.', 'ส.'],
-    monthNames: [
-      'มกราคม',
-      'กุมภาพันธ์',
-      'มีนาคม',
-      'เมษายน',
-      'พฤษภาคม',
-      'มิถุนายน',
-      'กรกฎาคม',
-      'สิงหาคม',
-      'กันยายน',
-      'ตุลาคม',
-      'พฤศจิกายน',
-      'ธันวาคม',
-    ],
-    monthNamesShort: ['ม.ค.', 'ก.พ.', 'มี.ค.', 'เม.ย.', 'พ.ค.', 'มิ.ย.', 'ก.ค.', 'ส.ค.', 'ก.ย.', 'ต.ค.', 'พ.ย.', 'ธ.ค.'],
-    chooseDate: 'เลือกวันที่',
-    chooseMonth: 'เลือกเดือน',
-    chooseYear: 'เลือกปี',
-    prevMonth: 'เดือนก่อนหน้า',
-    nextMonth: 'เดือนถัดไป',
-    prevYear: 'ปีก่อนหน้า',
-    nextYear: 'ปีถัดไป',
-    today: 'วันนี้',
-    clear: 'ล้าง',
-    firstDayOfWeek: 1,
-    showMonthAfterYear: false,
-    dateFormat: 'yy-mm-dd',
-  },
-}
-
 const previewTotals = computed(() => {
   const total = form.charges.reduce((sum, charge) => sum + lineAmount(charge), 0)
   const subtotal = total / (1 + VAT_RATE)
@@ -1139,14 +990,6 @@ const alertTitle = computed(() => {
   return t('manualInvoice.validationTitle')
 })
 
-watch(
-  locale,
-  (nextLocale) => {
-    syncPrimeVueDatePickerLocale(nextLocale)
-  },
-  { immediate: true },
-)
-
 watch(
   () => form.recipient.company_code,
   (companyCode) => {
@@ -1466,37 +1309,6 @@ function validationAria(fieldKey: string): Record<string, string | undefined> {
   }
 }
 
-function datePickerPt(testId: string, fieldKey: string): Record<string, unknown> {
-  return {
-    pcInputText: {
-      root: {
-        'data-testid': testId,
-        lang: locale.value,
-        ...validationAria(fieldKey),
-      },
-    },
-    panel: {
-      lang: locale.value,
-      'data-testid': `${testId}-panel`,
-    },
-  }
-}
-
-function syncPrimeVueDatePickerLocale(nextLocale: string): void {
-  const supportedLocale = normalizeDateLocale(nextLocale)
-  primeVue.config.locale = {
-    ...(primeVue.config.locale ?? primeVueDatePickerLocales['en-US']),
-    ...primeVueDatePickerLocales[supportedLocale],
-  }
-}
-
-function normalizeDateLocale(nextLocale: string): ManualInvoiceDateLocale {
-  if (nextLocale === 'en-US' || nextLocale === 'th-TH') {
-    return nextLocale
-  }
-  return 'zh-CN'
-}
-
 function chargeFieldKey(index: number, fieldName: ChargeFieldName): string {
   return `charge-${index}-${fieldName}`
 }
@@ -1688,40 +1500,6 @@ function datePartsToInputValue(parts: Intl.DateTimeFormatPart[]): string {
   return `${year}-${month}-${day}`
 }
 
-function createDatePickerModel(readValue: () => string, writeValue: (value: string) => void) {
-  return computed<Date | null>({
-    get: () => parseInputDateValue(readValue()),
-    set: (value) => {
-      writeValue(formatDatePickerValue(value))
-    },
-  })
-}
-
-function parseInputDateValue(readValue: string): Date | null {
-  const match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(readValue)
-  if (!match) {
-    return null
-  }
-  const year = Number(match[1])
-  const month = Number(match[2])
-  const day = Number(match[3])
-  const date = new Date(year, month - 1, day)
-  if (date.getFullYear() !== year || date.getMonth() !== month - 1 || date.getDate() !== day) {
-    return null
-  }
-  return date
-}
-
-function formatDatePickerValue(value: Date | null | undefined): string {
-  if (!(value instanceof Date) || Number.isNaN(value.getTime())) {
-    return ''
-  }
-  const year = value.getFullYear()
-  const month = String(value.getMonth() + 1).padStart(2, '0')
-  const day = String(value.getDate()).padStart(2, '0')
-  return `${year}-${month}-${day}`
-}
-
 function isRecord(value: unknown): value is Record<string, unknown> {
   return typeof value === 'object' && value !== null && !Array.isArray(value)
 }
@@ -1962,21 +1740,6 @@ function isRecord(value: unknown): value is Record<string, unknown> {
   min-width: 0;
 }
 
-.localized-date-picker {
-  display: block;
-  width: 100%;
-}
-
-.localized-date-picker :deep(.p-inputtext) {
-  width: 100%;
-  padding-right: 40px;
-}
-
-.localized-date-picker :deep(.p-datepicker-input-icon-container) {
-  right: 12px;
-  color: var(--th-color-navy-950);
-}
-
 .number-control {
   display: grid;
   grid-template-columns: minmax(0, 1fr) auto;
@@ -2414,11 +2177,3 @@ function isRecord(value: unknown): value is Record<string, unknown> {
   }
 }
 </style>
-
-<style>
-.manual-invoice-datepicker-panel {
-  z-index: 1200;
-  color: var(--th-color-navy-950);
-  font-family: inherit;
-}
-</style>