diff --git a/app/static/css/assiduites.css b/app/static/css/assiduites.css
index 701cdc9be..c22e38e8a 100644
--- a/app/static/css/assiduites.css
+++ b/app/static/css/assiduites.css
@@ -278,7 +278,7 @@
     padding: 20px;
     border: 1px solid #888;
     width: 80%;
-    height: 30%;
+    height: 40%;
     position: relative;
     border-radius: 10px;
 
diff --git a/app/static/js/assiduites.js b/app/static/js/assiduites.js
index d3264bc15..015c52573 100644
--- a/app/static/js/assiduites.js
+++ b/app/static/js/assiduites.js
@@ -1570,26 +1570,28 @@ function resetSelection() {
  */
 window.onload = () => {
   modal = document.getElementById("myModal");
-  closeBtn = document.querySelector(".close");
-  timeline = document.getElementById("timeline");
-  deleteBtn = document.getElementById("delete");
-  splitBtn = document.getElementById("split");
-  editBtn = document.getElementById("edit");
-  selectedAssiduite = null;
+  if (modal) {
+    closeBtn = document.querySelector(".close");
+    timeline = document.getElementById("timeline");
+    deleteBtn = document.getElementById("delete");
+    splitBtn = document.getElementById("split");
+    editBtn = document.getElementById("edit");
+    selectedAssiduite = null;
 
-  closeBtn?.addEventListener("click", closeModal);
+    closeBtn?.addEventListener("click", closeModal);
 
-  deleteBtn?.addEventListener("click", deleteAssiduiteModal);
-  splitBtn?.addEventListener("click", () => {
-    if (selectedAssiduite) {
-      splitAssiduiteModal(selectedAssiduite);
-    }
-  });
-  editBtn?.addEventListener("click", () => {
-    if (selectedAssiduite) {
-      editAssiduiteModal(selectedAssiduite);
-    }
-  });
+    deleteBtn?.addEventListener("click", deleteAssiduiteModal);
+    splitBtn?.addEventListener("click", () => {
+      if (selectedAssiduite) {
+        splitAssiduiteModal(selectedAssiduite);
+      }
+    });
+    editBtn?.addEventListener("click", () => {
+      if (selectedAssiduite) {
+        editAssiduiteModal(selectedAssiduite);
+      }
+    });
+  }
 };
 
 // <<== Gestion de la récupération d'informations ==>>
diff --git a/app/templates/assiduites/minitimeline.j2 b/app/templates/assiduites/minitimeline.j2
index ebde4d0c6..8de471d42 100644
--- a/app/templates/assiduites/minitimeline.j2
+++ b/app/templates/assiduites/minitimeline.j2
@@ -59,18 +59,18 @@
             block.style.width = `${widthPercentage}%`;
 
             if (assiduité.etat != "CRENEAU") {
-                if (isSingleEtud()) {
-                    block.addEventListener("click", () => {
-                        let deb = startDate.hours() + startDate.minutes() / 60;
-                        let fin = endDate.hours() + endDate.minutes() / 60;
-                        deb = Math.max(mt_start, deb);
-                        fin = Math.min(mt_end, fin);
+                block.addEventListener("click", () => {
+                    let deb = startDate.hours() + startDate.minutes() / 60;
+                    let fin = endDate.hours() + endDate.minutes() / 60;
+                    deb = Math.max(mt_start, deb);
+                    fin = Math.min(mt_end, fin);
 
-                        setPeriodValues(deb, fin);
+                    setPeriodValues(deb, fin);
+                    if (isSingleEtud()) {
                         updateSelectedSelect(getCurrentAssiduiteModuleImplId());
                         updateJustifyBtn();
-                    });
-                }
+                    }
+                });
                 //ajouter affichage assiduites on over
                 setupAssiduiteBuble(block, assiduité);
             }
@@ -272,7 +272,9 @@
         position: absolute;
         text-align: start;
         top: -40px;
-        transform: translateX(-50%)
+        transform: translateX(-50%);
+        z-index: 50;
+
     }
 
     .mini_tick::after {
diff --git a/app/templates/assiduites/signal_assiduites_diff.j2 b/app/templates/assiduites/signal_assiduites_diff.j2
index e0061e0b3..cecfe1469 100644
--- a/app/templates/assiduites/signal_assiduites_diff.j2
+++ b/app/templates/assiduites/signal_assiduites_diff.j2
@@ -4,7 +4,7 @@
 <div id="studentTable">
     <div class="thead">
         <div class="tr">
-            <div class="th sticky">Noms</div>
+            <div class="th sticky" order="ASC" onclick="reOrderEtudiants()">Noms</div>
             <button id="addColumn" class="floating-button">+</button>
         </div>
     </div>
@@ -52,7 +52,7 @@
     }
 
     .thead .tr .th {
-        height: 125px;
+        height: 200px;
         display: flex;
         justify-content: center;
         align-items: center;
@@ -61,11 +61,12 @@
 
     .th.sticky {
         z-index: 5;
+        cursor: pointer;
     }
 
     .th,
     .td {
-        padding: 10px;
+        padding: 20px;
         text-align: center;
         width: 200px;
         border: 1px solid #ddd;
@@ -124,6 +125,7 @@
     .th {
         background-color: #007BFF;
         color: white;
+        position: relative;
     }
 
     .tbody .tr:nth-child(even) {
@@ -143,12 +145,48 @@
     }
 
     #moduleimpl_select {
-        max-width: 175px;
+        max-width: 190px;
+    }
+
+    .btngroup {
+        width: 100%;
+        display: flex;
+        justify-content: space-between;
+        align-items: center;
+        flex-direction: row;
+    }
+
+    .btngroup>button {
+        background-color: transparent;
+        outline: none;
+        border: none;
+        cursor: pointer;
+        color: whitesmoke;
+    }
+
+    .close {
+        font-size: larger;
+    }
+
+    .activate {
+        font-size: large;
+    }
+
+    .th[activated] {
+        transition: all 0.5s;
+    }
+
+    .th[activated='false'] {
+        opacity: 0.5;
     }
 </style>
 <script>
     let verified = false;
     const etatDef = "{{etat_def}}";
+
+    let forceModule = "{{ forcer_module }}"
+    forceModule = forceModule == "True" ? true : false
+
     moment.tz.setDefault("Etc/UTC");
     function createColumn() {
         let table = document.getElementById("studentTable");
@@ -156,11 +194,22 @@
         th.classList.add("th");
         const col_id = `${document.querySelectorAll("[col]").length + 1}`;
         th.setAttribute("col", col_id);
+        th.setAttribute("activated", "true");
         th.innerHTML = `
       <div class="mini-form">
+          <div class="btngroup">
+                <button class="activate" onclick="toggleColumn(${col_id})">Désactiver</button>
+                <button class="close" onclick="removeColumn(this)">x</button>
+          </div>
           <input type="datetime-local" id="dateStart">
           <input type="datetime-local" id="dateEnd">
           {{moduleimpl_select|safe}}
+          <select name="mass_action_${col_id}" id="mass_action_${col_id}" onchange="setEtatCol(${col_id},this.value)">
+            <option value="">Sélectionner une assiduité</option>
+            <option value="0">Présent</option>
+            <option value="1">Retard</option>
+            <option value="2">Absent</option>
+          </select>
       </div>
       `;
         table
@@ -193,9 +242,68 @@
         }
     }
 
+    function reOrderEtudiants() {
+        const th = document.querySelector(".th.sticky");
+        let lines = [...document.querySelectorAll('.tr[etudid]')];
+        const tbody = document.querySelector('.tbody')
+
+        let order = (a, b) => { return a > b }
+
+        if (th.getAttribute("order") == "ASC") {
+            order = (a, b) => { return b > a }
+            th.setAttribute("order", "DESC")
+        } else {
+            th.setAttribute("order", "ASC")
+        }
+
+        lines = lines.sort((a, b) => {
+            const nameA = a.querySelector(".td.sticky").textContent.split(" ").pop();
+            const nameB = b.querySelector(".td.sticky").textContent.split(" ").pop();
+            return order(nameA, nameB)
+        })
+
+        tbody.innerHTML = "";
+        tbody.append(...lines)
+    }
+
+    function toggleColumn(colId) {
+        const column = document.querySelector(`[col='${colId}']`)
+        const btn = column.querySelector(".activate");
+        if (column.getAttribute('activated') == "true") {
+            column.setAttribute("activated", "false");
+            btn.textContent = "Activer"
+        } else {
+            column.setAttribute("activated", "true");
+            btn.textContent = "Déactiver"
+        }
+    }
+
+    function previousCol(column) {
+        const cols = [...document.querySelectorAll("[col]")]
+        let previousCol = null;
+
+        let i = 1;
+
+        while (i < cols.length) {
+            previousCol = cols[i - 1];
+            if (cols[i] == column)
+                break;
+            i++;
+        }
+
+        return previousCol
+
+    }
+
+    function removeColumn(element) {
+        const col = element.parentElement.parentElement.parentElement;
+        const col_id = col.getAttribute("col");
+        document.querySelectorAll(`[col='${col_id}'],[colid='${col_id}']`).forEach((el) => { el.remove() })
+    }
+
     function defaultDate(element) {
-        const num = element.parentElement.parentElement.getAttribute("col") - 1;
-        const last = [...document.querySelectorAll(`[col='${num}'] #dateEnd`)].pop();
+        const num = previousCol(element.parentElement.parentElement)?.getAttribute("col");
+        const last = document.querySelector(`[col='${num}'] #dateEnd`);
         let date = undefined;
         if (last == undefined) {
             date = moment().tz("Europe/Paris").format("YYYY-MM-DDTHH:mm");
@@ -218,6 +326,17 @@
         );
     }
 
+    function setEtatCol(colId, etatId) {
+        const tds = [...document.querySelectorAll(`.td[colid='${colId}']`)]
+        tds.forEach((td) => {
+            let inputs = [...td.querySelectorAll("input")]
+            inputs.forEach((el) => { el.checked = false })
+            if (etatId != "") {
+                inputs[Number.parseInt(etatId)].checked = true;
+            }
+        })
+    }
+
     function getEtatCol(colId) {
         const etats = {};
         const tds = [...document.querySelectorAll(`.td[colid='${colId}']`)]
@@ -266,6 +385,8 @@
 
         cols.forEach((col) => {
             const col_id = col.getAttribute("col");
+            if (col.getAttribute("activated") == "false") return;
+            toggleColumn(col_id);
             const etats = getEtatCol(col_id);
 
             const inputDeb = col.querySelector("#dateStart").value;
@@ -273,10 +394,27 @@
             const moduleSelect = col.querySelector("#moduleimpl_select").value;
 
             if (inputDeb == "" || inputFin == "") {
-                errors.push(`La colonne n°${col_id} n'est pas valide`);
+                errors.push(`La période de la colonne n°${col_id} n'est pas valide`);
+                return;
+            }
+
+            const d_debut = moment(inputDeb)
+            const d_fin = moment(inputFin)
+            const testPeriode = [
+                d_debut.isBefore("{{formsemestre_date_debut}}"),
+                d_debut.isAfter("{{formsemestre_date_fin}}"),
+                d_fin.isBefore("{{formsemestre_date_debut}}"),
+                d_fin.isAfter("{{formsemestre_date_fin}}"),
+            ]
+            if (testPeriode.some((e) => e)) {
+                errors.push(`La période de la colonne n°${col_id} n'est pas dans le semestre`);
+                return;
+            }
+
+            if (forceModule && moduleSelect == "") {
+                errors.push(`Le module de la colonne n°${col_id} n'a pas été entré. (Préférence de semestre)`);
                 return;
             }
-            // TODO Mettre une erreur lorsque moduleimpl forcé (pref)
             // TODO Mettre une erreur lorsque assiduité forcé (pref)
 
             Object.keys(etats).forEach((key) => {
@@ -297,7 +435,9 @@
 
             openAlertModal("Erreur(s) détéctée(s)", texte)
         } else {
-            createAllAssiduites(assiduites);
+            if (assiduites.length > 0) {
+                createAllAssiduites(assiduites);
+            }
         }
 
 
diff --git a/app/templates/assiduites/signal_assiduites_group.j2 b/app/templates/assiduites/signal_assiduites_group.j2
index 7bf85c028..294499d96 100644
--- a/app/templates/assiduites/signal_assiduites_group.j2
+++ b/app/templates/assiduites/signal_assiduites_group.j2
@@ -45,7 +45,7 @@
             <div class="action-buttons">
                 <button id="delete" class="btnPrompt" disabled>Supprimer</button>
                 <button id="split" class="btnPrompt" disabled>Séparer</button>
-                <button id="edit" class="btnPrompt" disabled>Modifier</button>
+                <button id="edit" class="btnPrompt" disabled>Modifier l'état</button>
             </div>
         </div>
 
diff --git a/app/views/assiduites.py b/app/views/assiduites.py
index fdb6a95f5..22bb7f6cb 100644
--- a/app/views/assiduites.py
+++ b/app/views/assiduites.py
@@ -489,7 +489,6 @@ def get_etat_abs_date():
 @permission_required(Permission.ScoAbsChange)
 def signal_assiduites_diff():
     group_ids: list[int] = request.args.get("group_ids", None)
-    etudid: int = request.args.get("etudid", None)
     formsemestre_id: int = request.args.get("formsemestre_id", -1)
     etudiants: list[dict] = []
 
@@ -503,9 +502,6 @@ def signal_assiduites_diff():
 
     formsemestre: FormSemestre = FormSemestre.query.get_or_404(formsemestre_id)
 
-    if etudid is not None:
-        etudiants.append(sco_etud.get_etud_info(etudid=int(etudid), filled=True)[0])
-
     if group_ids is None:
         group_ids = []
     else:
@@ -514,6 +510,13 @@ def signal_assiduites_diff():
 
     groups_infos = sco_groups_view.DisplayedGroupsInfos(group_ids)
 
+    if not groups_infos.members:
+        return (
+            html_sco_header.sco_header(page_title="Assiduités Différées")
+            + "<h3>Aucun étudiant ! </h3>"
+            + html_sco_header.sco_footer()
+        )
+
     etudiants.extend(
         [
             sco_etud.get_etud_info(etudid=m["etudid"], filled=True)[0]
@@ -553,7 +556,14 @@ def signal_assiduites_diff():
             "assiduites/signal_assiduites_diff.j2",
             etudiants=etudiants,
             etat_def=sco_preferences.get_preference("assi_etat_defaut"),
+            formsemestre_date_debut=str(formsemestre.date_debut),
+            formsemestre_date_fin=str(formsemestre.date_fin),
             moduleimpl_select=_module_selector(formsemestre),
+            forcer_module=sco_preferences.get_preference(
+                "forcer_module",
+                formsemestre_id=formsemestre_id,
+                dept_id=g.scodoc_dept_id,
+            ),
             gr=gr_tit,
             sem=sem["titre_num"],
         ),