diff --git a/frontend/src/components/Admin/AdminPerm/adminPermForm.tsx b/frontend/src/components/Admin/AdminPerm/adminPermForm.tsx
index d68a57a..6c06e2f 100644
--- a/frontend/src/components/Admin/AdminPerm/adminPermForm.tsx
+++ b/frontend/src/components/Admin/AdminPerm/adminPermForm.tsx
@@ -15,7 +15,7 @@ import { getUsers } from "../../../services/requests/user.service";
 
 import { Permanence } from "../../../interfaces/permanence.interface";
 import { User } from "../../../interfaces/user.interface";
-import { formatDateForInput } from "../../utils/datetime_utils";
+import { formatDateForDB, formatDateForInput } from "../../utils/datetime_utils";
 
 interface PermanenceFormProps {
   editMode: boolean;
@@ -58,8 +58,8 @@ const PermanenceForm = ({
       setName(editPermanence.name);
       setDesc(editPermanence.description);
       setLocation(editPermanence.location);
-      setStartAt(formatDateForInput(editPermanence.start_at));
-      setEndAt(formatDateForInput(editPermanence.end_at));
+      setStartAt(formatDateForInput(editPermanence.start_at)); 
+      setEndAt(formatDateForInput(editPermanence.end_at));     
       setCapacity(editPermanence.capacity);
       setDifficulty(editPermanence.difficulty);
       if (editPermanence.respo) {
@@ -82,29 +82,30 @@ const PermanenceForm = ({
       return;
     }
 
-    const respoId =
-      respo && !isNaN(Number(respo.userId)) ? Number(respo.userId) : null;
+
+    let respoId = respo && !isNaN(Number(respo.userId)) ? Number(respo.userId) : null;
+
 
     try {
       const payload = {
         name,
         description: desc,
         location,
-        start_at: formatDateForInput(startAt),
-        end_at: formatDateForInput(endAt),
+        start_at: formatDateForDB(startAt), // ✅ en UTC
+        end_at: formatDateForDB(endAt),     // ✅ en UTC
         capacity,
         difficulty,
         respoId,
       };
-
-      if (editMode && editPermanence) {
-        await updatePermanence(editPermanence.id, payload);
-        Swal.fire("Succès", "Permanence mise à jour", "success");
-        onCancelEdit();
-      } else {
-        await createPermanence(payload);
-        Swal.fire("Succès", "Permanence créée", "success");
-      }
+      
+        if (editMode && editPermanence) {
+          await updatePermanence(editPermanence.id, payload);
+          Swal.fire("Succès", "Permanence mise à jour", "success");
+          onCancelEdit();
+        } else {
+          await createPermanence(payload);
+          Swal.fire("Succès", "Permanence créée", "success");
+        }
 
       resetForm();
       onRefresh();
diff --git a/frontend/src/components/utils/datetime_utils.ts b/frontend/src/components/utils/datetime_utils.ts
index c266602..db37c17 100644
--- a/frontend/src/components/utils/datetime_utils.ts
+++ b/frontend/src/components/utils/datetime_utils.ts
@@ -1,19 +1,39 @@
-// Pour l'input datetime-local
+// Pour préremplir un <input type="datetime-local">
+// On reçoit une date en UTC (string ISO venant de la DB)
+// On la convertit en locale (Europe/Paris) et on renvoie une string sans timezone
 export const formatDateForInput = (date?: string | null) => {
   if (!date) return "";
   const localDate = new Date(date);
-  if (isNaN(localDate.getTime())) return ""; // date invalide
-  const offsetDate = new Date(localDate.getTime() - localDate.getTimezoneOffset() * 60000);
-  return offsetDate.toISOString().slice(0, 16);
+  if (isNaN(localDate.getTime())) return "";
+
+  // Construire YYYY-MM-DDTHH:mm en LOCAL
+  const year = localDate.getFullYear();
+  const month = String(localDate.getMonth() + 1).padStart(2, "0");
+  const day = String(localDate.getDate()).padStart(2, "0");
+  const hours = String(localDate.getHours()).padStart(2, "0");
+  const minutes = String(localDate.getMinutes()).padStart(2, "0");
+
+  return `${year}-${month}-${day}T${hours}:${minutes}`;
+};
+
+
+// Pour envoyer vers la DB
+// On reçoit une string "YYYY-MM-DDTHH:mm" venant de l'input datetime-local
+// On la convertit en UTC ISO (toujours ce que ta DB attend)
+export const formatDateForDB = (inputValue?: string | null) => {
+  if (!inputValue) return null;
+  const localDate = new Date(inputValue); // interprété en local
+  if (isNaN(localDate.getTime())) return null;
+  return localDate.toISOString(); // UTC
 };
 
-// Pour affichage lisible en français
+// Pour affichage lisible en français (Europe/Paris)
 export const formatDateForDisplay = (date?: string | null) => {
   if (!date) return "";
   const localDate = new Date(date);
   if (isNaN(localDate.getTime())) return "";
   return localDate.toLocaleString("fr-FR", {
-    timeZone: "Europe/Paris", // évite les surprises
+    timeZone: "Europe/Paris",
     weekday: "long",
     year: "numeric",
     month: "long",
diff --git a/frontend/src/services/requests/permanence.service.ts b/frontend/src/services/requests/permanence.service.ts
index 2a88bf7..a5c824f 100644
--- a/frontend/src/services/requests/permanence.service.ts
+++ b/frontend/src/services/requests/permanence.service.ts
@@ -29,8 +29,8 @@ export const createPermanence = async (permanenceData: {
   name: string;
   description: string;
   location: string;
-  start_at: string;
-  end_at: string;
+  start_at: string | null;
+  end_at: string | null;
   capacity: number;
   difficulty : number;
   respoId: number | null;
@@ -88,8 +88,8 @@ export const updatePermanence = async ( permId: number, permanenceData: {
     name: string;
     description: string;
     location: string;
-    start_at: string;
-    end_at: string;
+    start_at: string | null;
+    end_at: string | null;
     capacity: number;
     difficulty : number;
     respoId: number | null;