diff --git a/app/templates/assiduites/widgets/differee.j2 b/app/templates/assiduites/widgets/differee.j2
index 4b4e3cd4..250545c2 100644
--- a/app/templates/assiduites/widgets/differee.j2
+++ b/app/templates/assiduites/widgets/differee.j2
@@ -274,6 +274,7 @@
 
 <script>
     const assi_etat_defaut = "{{assi_etat_defaut}}";
+    const periode_defaut = {{periode_defaut}};
     {% if scu.is_assiduites_module_forced(request.args.get('formsemestre_id', None)) %}
     window.forceModule = true;
     {% else %}
@@ -293,6 +294,7 @@
 
 
     function createColumn(dateStart = "", dateEnd = "", moduleimpl_id = "") {
+        // TODO Choix dates : utiliser même chose que page ajout_assiduite_etud
         let table = document.getElementById("studentTable");
         let th = document.createElement("div");
         th.classList.add("th", "error");
@@ -452,7 +454,7 @@
                 const el = element.parentElement.querySelector("#dateEnd");
                 const el2 = element.parentElement.querySelector("#dateStart");
                 const newDate = new Date(el2.valueAsDate)
-                    .add(2, "hours");
+                    .add(periode_defaut, "hours");
                 el.valueAsDate = newDate;
 
                 const colid = element.parentElement.parentElement.getAttribute('col');
diff --git a/app/views/assiduites.py b/app/views/assiduites.py
index 243399f9..11406ee6 100644
--- a/app/views/assiduites.py
+++ b/app/views/assiduites.py
@@ -2078,10 +2078,17 @@ def _differee(
         dept_id=g.scodoc_dept_id,
     )
 
+    periode_defaut = sco_preferences.get_preference(
+        "periode_defaut",
+        formsemestre_id=formsemestre_id,
+        dept_id=g.scodoc_dept_id,
+    )
+
     return render_template(
         "assiduites/widgets/differee.j2",
         etudiants=etudiants,
         assi_etat_defaut=assi_etat_defaut,
+        periode_defaut=periode_defaut,
         forcer_module=forcer_module,
         moduleimpl_select=moduleimpl_select,
         date=date,