diff --git a/apps/api/src/common/excel.ts b/apps/api/src/common/excel.ts
index aaae836..29aba3c 100644
--- a/apps/api/src/common/excel.ts
+++ b/apps/api/src/common/excel.ts
@@ -170,9 +170,34 @@ export function parseAmount(raw?: string): number | null {
 }
 
 /** تاریخ تولد: سال زیر ۱۷۰۰ شمسی است، سال ۱۷۰۰ به بعد میلادی. ظهر UTC تا روز جابه‌جا نشود. */
+/** «۲۰۲۴-۰۵-۰۱T۱۹:۳۰:۰۰Z» و مشابه: لحظهٔ دقیق با منطقهٔ زمانی */
+const ZONED_TIMESTAMP = /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}(:\d{2}(\.\d+)?)?(Z|[+-]\d{2}:?\d{2})$/i;
+
+function tehranCalendarDay(d: Date): { y: number; m: number; d: number } {
+  const [y, m, day] = new Intl.DateTimeFormat('en-CA', {
+    timeZone: 'Asia/Tehran',
+    year: 'numeric',
+    month: '2-digit',
+    day: '2-digit',
+  })
+    .format(d)
+    .split('-')
+    .map(Number);
+  return { y, m, d: day };
+}
+
 export function parseBirthDate(raw?: string | null): Date | null {
   const text = toAsciiDigits(String(raw ?? '')).trim();
   if (!text || text === '-' || text === '0' || text === '0000-00-00') return null;
+  // تاریخ تولد فقط «روز» است. لحظهٔ UTC (مثلاً نیمه‌شب تهران که به روز قبلِ UTC می‌افتد)
+  // باید با تقویم تهران به روز تبدیل شود، نه با بریدن بخش تاریخِ UTC.
+  if (ZONED_TIMESTAMP.test(text)) {
+    const instant = new Date(text);
+    if (!Number.isNaN(instant.getTime())) {
+      const day = tehranCalendarDay(instant);
+      return new Date(Date.UTC(day.y, day.m - 1, day.d, 12, 0, 0));
+    }
+  }
   const datePart = text.split(/[T\s]/)[0] ?? text;
   const match = /^(\d{3,4})[\/\-.](\d{1,2})[\/\-.](\d{1,2})$/.exec(datePart);
   if (!match) {
diff --git a/apps/web/src/views/LeadDetailView.vue b/apps/web/src/views/LeadDetailView.vue
index a50eb57..f2dec61 100644
--- a/apps/web/src/views/LeadDetailView.vue
+++ b/apps/web/src/views/LeadDetailView.vue
@@ -206,9 +206,7 @@ async function saveEdit() {
       region: editForm.value.region.trim() || null,
       source: editForm.value.source.trim() || null,
       instagram: editForm.value.instagram.trim() || null,
-      birthDate: editForm.value.birthDate
-        ? (parseLocalInput(editForm.value.birthDate)?.toISOString() ?? null)
-        : null,
+      birthDate: editForm.value.birthDate || null,
       trade: editForm.value.trade.trim() || null,
       notes: editForm.value.notes.trim() || null,
     });
diff --git a/apps/web/src/views/PersonFormView.vue b/apps/web/src/views/PersonFormView.vue
index 3f10955..0c2df10 100644
--- a/apps/web/src/views/PersonFormView.vue
+++ b/apps/web/src/views/PersonFormView.vue
@@ -36,7 +36,7 @@ import {
 import { api } from '@/lib/api';
 import type { CompanyDto, CreatePersonRequest, PersonDto, PersonMood } from '@mento/shared';
 import { PERSON_MOOD_LABELS, PERSON_MOODS } from '@/lib/person-mood';
-import { formatLocalDateInput, parseLocalInput, toFaDigits } from '@/lib/jalali';
+import { formatLocalDateInput, toFaDigits } from '@/lib/jalali';
 import JalaliDateInput from '@/components/JalaliDateInput.vue';
 import {
   filterPhoneContacts,
@@ -327,7 +327,7 @@ function payload(): CreatePersonRequest {
     position: position.value || undefined,
     website: website.value || undefined,
     instagram: instagram.value || undefined,
-    birthDate: birthDate.value ? parseLocalInput(birthDate.value)?.toISOString() ?? null : null,
+    birthDate: birthDate.value || null,
     referrer: referrer.value || undefined,
     addresses: addresses.value.map((a) => a.trim()).filter(Boolean),
     notes: notes.value || undefined,