diff --git a/app/scodoc/sco_edt_cal.py b/app/scodoc/sco_edt_cal.py
index 7d63add014..476546f9b4 100644
--- a/app/scodoc/sco_edt_cal.py
+++ b/app/scodoc/sco_edt_cal.py
@@ -41,50 +41,58 @@ from app.scodoc.sco_exceptions import ScoValueError
 import app.scodoc.sco_utils as scu
 
 
-def formsemestre_load_calendar(
-    formsemestre: FormSemestre,
-) -> icalendar.cal.Calendar | None:
-    """Load ics data, return calendar or None if not configured or not available"""
-    edt_id = formsemestre.get_edt_id()
-    if not edt_id:
-        flash(
-            "accès aux emplois du temps non configuré pour ce semestre (pas d'edt_id)"
-        )
-        return None
+def get_ics_filename(edt_id: str) -> str:
+    "Le chemin vers l'ics de cet edt_id"
     edt_ics_path = ScoDocSiteConfig.get("edt_ics_path")
     if not edt_ics_path.strip():
         return None
-    ics_filename = edt_ics_path.format(edt_id=edt_id)
+    return edt_ics_path.format(edt_id=edt_id)
+
+
+def formsemestre_load_calendar(
+    formsemestre: FormSemestre = None, edt_id: str = None
+) -> tuple[bytes, icalendar.cal.Calendar]:
+    """Load ics data, return raw ics and decoded calendar.
+    Raises ScoValueError if not configured or not available or invalid format.
+    """
+    if edt_id is None and formsemestre:
+        edt_id = formsemestre.get_edt_id()
+    if not edt_id:
+        raise ScoValueError(
+            "accès aux emplois du temps non configuré pour ce semestre (pas d'edt_id)"
+        )
+    ics_filename = get_ics_filename(edt_id)
     try:
         with open(ics_filename, "rb") as file:
             log(f"Loading edt from {ics_filename}")
+            data = file.read()
             try:
-                calendar = icalendar.Calendar.from_ical(file.read())
+                calendar = icalendar.Calendar.from_ical(data)
             except ValueError as exc:
                 log(
                     f"""formsemestre_load_calendar: error importing ics for {
-                        formsemestre}\npath='{ics_filename}'"""
+                        formsemestre or ''}\npath='{ics_filename}'"""
                 )
                 raise ScoValueError(
                     f"calendrier ics illisible (edt_id={edt_id})"
                 ) from exc
     except FileNotFoundError as exc:
         log(
-            f"formsemestre_load_calendar: ics not found for {formsemestre}\npath='{ics_filename}'"
+            f"formsemestre_load_calendar: ics not found for {formsemestre or ''}\npath='{ics_filename}'"
         )
         raise ScoValueError(
             f"Fichier ics introuvable (filename={ics_filename})"
         ) from exc
     except PermissionError as exc:
         log(
-            f"""formsemestre_load_calendar: permission denied for {formsemestre
+            f"""formsemestre_load_calendar: permission denied for {formsemestre or ''
                                                                  }\npath='{ics_filename}'"""
         )
         raise ScoValueError(
             f"Fichier ics inaccessible: vérifier permissions (filename={ics_filename})"
         ) from exc
 
-    return calendar
+    return data, calendar
 
 
 # --- Couleurs des évènements emploi du temps
@@ -178,7 +186,7 @@ def formsemestre_edt_dict(formsemestre: FormSemestre) -> list[dict]:
 def _load_and_convert_ics(formsemestre: FormSemestre) -> list[dict]:
     "chargement fichier, filtrage et extraction des identifiants."
     # Chargement du calendier ics
-    calendar = formsemestre_load_calendar(formsemestre)
+    _, calendar = formsemestre_load_calendar(formsemestre)
     if not calendar:
         return []
     # --- Paramètres d'extraction
@@ -236,7 +244,8 @@ def _load_and_convert_ics(formsemestre: FormSemestre) -> list[dict]:
                 edt_group = extract_event_data(
                     event, edt_ics_group_field, edt_ics_group_pattern
                 )
-                # si pas de groupe dans l'event, oi si groupe non reconnu, prend toute la promo ("tous")
+                # si pas de groupe dans l'event, ou si groupe non reconnu,
+                # prend toute la promo ("tous")
                 group: GroupDescr = (
                     edt2group.get(edt_group, default_group)
                     if edt_group
diff --git a/app/templates/assiduites/pages/config_assiduites.j2 b/app/templates/assiduites/pages/config_assiduites.j2
index 7522968a9c..3d75e9b8ce 100644
--- a/app/templates/assiduites/pages/config_assiduites.j2
+++ b/app/templates/assiduites/pages/config_assiduites.j2
@@ -10,9 +10,50 @@ div.config-section {
     margin-right: -15px;
     margin-left: -15px;
 }
-</style>
-{% endblock %}
 
+#zone-test {
+    margin-bottom: 12px;
+}
+#raw-ics-sample-zone {
+    display: none;
+}
+#raw-ics-sample-zone>div {
+    font-style: italic;
+}
+#test_load_ics:disabled {
+    background-color: gray;
+    color: white; /* Optional: change text color if needed */
+    cursor: not-allowed;
+}
+</style>
+{% endblock styles %}
+
+
+{% block scripts %}
+{{ super() }}
+
+<script>
+function update_test_button_state() {
+    var inputValue = document.getElementById('test_edt_id').value;
+    document.getElementById('test_load_ics').disabled = inputValue.length === 0;
+}
+
+async function load_ics_sample() {
+    var edt_id = document.getElementById('test_edt_id').value;
+    try {
+        const response = await fetch(`${SCO_URL}/../ics_raw_sample/${edt_id}`);
+        if (!response.ok) {
+            throw new Error(`HTTP error! status: ${response.status}`);
+        }
+        const data = await response.text();
+        document.getElementById('raw-ics-sample').value = data;
+        document.getElementById('raw-ics-sample-zone').style.display = 'block';
+    } catch (error) {
+        console.error('Error fetching data: ', error);
+    }
+}
+</script>
+{% endblock scripts %}
 
 {% block app_content %}
 <div class="row">
@@ -46,6 +87,18 @@ affectent notamment les comptages d'absences de tous les bulletins des
                     {{ wtf.form_field(form.edt_ics_path) }}
                 </div>
 
+                <div id="zone-test">
+                    Pour essayer, indiquer un <tt>edt_id</tt> :
+                    <input type="text" id="test_edt_id" oninput="update_test_button_state()" size="12" />
+                    <button id="test_load_ics" type="button" onclick="load_ics_sample()" disabled>
+                    Essayer de charger l'ics</button>
+                    <div id="raw-ics-sample-zone">
+                        <div>Voici un évènement chargé au milieu de ce calendrier:
+                        </div>
+                        <textarea id="raw-ics-sample" rows="13" cols="90">
+                        </textarea>
+                    </div>
+                </div>
                 <div class="config-section">Extraction des identifiants depuis les calendriers</div>
                 <div class="help">
                 Indiquer ici comment récupérer les informations (titre, groupe, module)
diff --git a/app/views/scodoc.py b/app/views/scodoc.py
index 4d5af816f9..6c30eec34a 100644
--- a/app/views/scodoc.py
+++ b/app/views/scodoc.py
@@ -81,7 +81,7 @@ from app.models import (
 from app.models import departements
 from app.models.config import PersonalizedLink
 
-
+from app.scodoc import sco_edt_cal
 from app.scodoc import sco_find_etud
 from app.scodoc import sco_logos
 from app.scodoc import sco_utils as scu
@@ -376,6 +376,24 @@ def config_assiduites():
     )
 
 
+@bp.route("/ScoDoc/ics_raw_sample/<string:edt_id>")
+@admin_required
+def ics_raw_sample(edt_id: str):
+    "Renvoie un extrait de l'ics brut, pour aider à configurer les extractions"
+    try:
+        raw_ics, _ = sco_edt_cal.formsemestre_load_calendar(edt_id=edt_id)
+    except ScoValueError as exc:
+        return exc.args[0]
+    try:
+        ics = raw_ics.decode(scu.SCO_ENCODING)
+    except SyntaxError:
+        return f"Erreur lors de la conversion vers {scu.SCO_ENCODING}"
+    evs = ics.split("BEGIN:VEVENT")
+    if len(evs) < 1:
+        return "pas d'évènements VEVENT détectés dans ce fichier"
+    return "BEGIN:VEVENT" + evs[len(evs) // 2]
+
+
 @bp.route("/ScoDoc/config_codes_decisions", methods=["GET", "POST"])
 @admin_required
 def config_codes_decisions():