diff --git a/src/composables/usePersianDate.js b/src/composables/usePersianDate.js
index de1cc4a..a4c890e 100644
--- a/src/composables/usePersianDate.js
+++ b/src/composables/usePersianDate.js
@@ -19,34 +19,49 @@ export function usePersianDate() {
     return result;
   };
 
-  const formatJalali = (date, formatStr = 'YYYY/MM/DD') => {
+  const formatJalali = (date, formatStr = 'jYYYY/jMM/jDD') => {
     if (!date) return '-';
     try {
-      return moment(date).locale('fa').format(formatStr);
+      return toPersianDigits(moment(date).locale('fa').format(formatStr));
     } catch (e) {
       return '-';
     }
   };
 
   const formatJalaliWithTime = (date) => {
-    return formatJalali(date, 'YYYY/MM/DD - HH:mm');
+    return formatJalali(date, 'jYYYY/jMM/jDD - HH:mm');
   };
 
-  const jalaliToIso = (jalaliStr) => {
-    if (!jalaliStr) return null;
+  const toJalaliPickerValue = (value) => {
+    if (!value) return '';
     try {
-      const latinStr = toLatinDigits(jalaliStr);
-      return moment(latinStr, 'jYYYY/jMM/jDD').toISOString();
+      return moment(value).locale('fa').format('jYYYY/jMM/jDD');
     } catch (e) {
-      return null;
+      return '';
     }
   };
 
+  const toGregorianIso = (jalaliValue) => {
+    if (!jalaliValue) return undefined;
+    if (jalaliValue instanceof Date) return jalaliValue.toISOString();
+    try {
+      const latin = toLatinDigits(String(jalaliValue));
+      const m = moment(latin, 'jYYYY/jMM/jDD');
+      return m.isValid() ? m.toDate().toISOString() : undefined;
+    } catch (e) {
+      return undefined;
+    }
+  };
+
+  const jalaliToIso = (jalaliStr) => toGregorianIso(jalaliStr) || null;
+
   return {
     toPersianDigits,
     toLatinDigits,
     formatJalali,
     formatJalaliWithTime,
+    toJalaliPickerValue,
+    toGregorianIso,
     jalaliToIso
   };
 }
diff --git a/src/views/payments/PaymentDetailView.vue b/src/views/payments/PaymentDetailView.vue
index fa84cd9..afe67d2 100644
--- a/src/views/payments/PaymentDetailView.vue
+++ b/src/views/payments/PaymentDetailView.vue
@@ -235,7 +235,7 @@ import DatePicker from 'vue3-persian-datetime-picker';
 
 const route = useRoute();
 const paymentId = route.params.id;
-const { toPersianDigits, formatJalali } = usePersianDate();
+const { toPersianDigits, formatJalali, toJalaliPickerValue, toGregorianIso } = usePersianDate();
 const { showSuccess, showError } = useToast();
 
 const payment = ref(null);
@@ -293,6 +293,8 @@ const fetchPayment = async () => {
 const handleRecordTransaction = async () => {
   if (!trxForm.amount) { showError('لطفا مبلغ را وارد کنید'); return; }
   if (!trxForm.dueDate) { showError('لطفا تاریخ سررسید را وارد کنید'); return; }
+  const dueDate = toGregorianIso(trxForm.dueDate);
+  if (!dueDate) { showError('تاریخ سررسید نامعتبر است'); return; }
   if (trxForm.status === 'paid' && !trxForm.receiptNumber) {
     showError('لطفا شماره فیش یا پیگیری را وارد کنید');
     return;
@@ -303,13 +305,14 @@ const handleRecordTransaction = async () => {
     const payload = {
       amount: trxForm.amount,
       status: trxForm.status,
-      dueDate: trxForm.dueDate,
+      dueDate,
       notes: trxForm.notes || undefined
     };
     if (trxForm.status === 'paid') {
       payload.method = trxForm.method;
       payload.receiptNumber = trxForm.receiptNumber;
-      if (trxForm.date) payload.date = trxForm.date;
+      const paymentDate = toGregorianIso(trxForm.date);
+      if (paymentDate) payload.date = paymentDate;
     }
 
     const res = await paymentApi.recordTransaction(paymentId, payload);
@@ -330,8 +333,8 @@ const openEditTransaction = (trx) => {
   editForm.status = trx.status || (trx.date ? 'paid' : 'pending');
   editForm.method = trx.method || 'card';
   editForm.receiptNumber = trx.receiptNumber || '';
-  editForm.dueDate = trx.dueDate || '';
-  editForm.date = trx.date || '';
+  editForm.dueDate = toJalaliPickerValue(trx.dueDate);
+  editForm.date = toJalaliPickerValue(trx.date);
   editForm.notes = trx.notes || '';
   showEditModal.value = true;
 };
@@ -345,19 +348,24 @@ const handleUpdateTransaction = async () => {
     showError('لطفا تاریخ سررسید را وارد کنید');
     return;
   }
+  const dueDate = toGregorianIso(editForm.dueDate);
+  if (!dueDate) {
+    showError('تاریخ سررسید نامعتبر است');
+    return;
+  }
 
   isSubmittingEdit.value = true;
   try {
     const payload = {
       amount: editForm.amount,
       status: editForm.status,
-      dueDate: editForm.dueDate,
+      dueDate,
       notes: editForm.notes
     };
     if (editForm.status === 'paid') {
       payload.method = editForm.method;
       payload.receiptNumber = editForm.receiptNumber;
-      payload.date = editForm.date || undefined;
+      payload.date = toGregorianIso(editForm.date);
     }
 
     const res = await paymentApi.updateTransaction(editingTransactionId.value, payload);
diff --git a/src/views/payments/PaymentListView.vue b/src/views/payments/PaymentListView.vue
index dac5efe..f6f8804 100644
--- a/src/views/payments/PaymentListView.vue
+++ b/src/views/payments/PaymentListView.vue
@@ -198,7 +198,7 @@ import Checkbox from 'primevue/checkbox';
 import Textarea from 'primevue/textarea';
 import DatePicker from 'vue3-persian-datetime-picker';
 
-const { toPersianDigits, formatJalali } = usePersianDate();
+const { toPersianDigits, formatJalali, toGregorianIso } = usePersianDate();
 const { showSuccess, showError } = useToast();
 
 const {
@@ -326,6 +326,8 @@ const handleCreatePayment = async () => {
   if (!createForm.user) { showError('لطفا کاربر را انتخاب کنید'); return; }
   if (!createForm.amount) { showError('لطفا مبلغ را وارد کنید'); return; }
   if (!createForm.dueDate) { showError('لطفا تاریخ سررسید را وارد کنید'); return; }
+  const dueDate = toGregorianIso(createForm.dueDate);
+  if (!dueDate) { showError('تاریخ سررسید نامعتبر است'); return; }
 
   if (hasDiscount.value && (createForm.discount || 0) > createForm.amount) {
     showError('مبلغ تخفیف نمی‌تواند بیشتر از مبلغ کل باشد');
@@ -336,6 +338,7 @@ const handleCreatePayment = async () => {
   try {
     await paymentApi.create({
       ...createForm,
+      dueDate,
       discount: hasDiscount.value ? (createForm.discount || 0) : 0,
       notify: { ...createNotify }
     });