diff --git a/backend/controllers/diaryDateActivityController.js b/backend/controllers/diaryDateActivityController.js
index 3802a47..d617b5d 100644
--- a/backend/controllers/diaryDateActivityController.js
+++ b/backend/controllers/diaryDateActivityController.js
@@ -79,11 +79,23 @@ export const getDiaryDateActivities = async (req, res) => {
 export const addGroupActivity = async(req, res) => {
     try {
         const { authcode: userToken } = req.headers;
-        const { clubId, diaryDateId, groupId, activity } = req.body;
-        const activityItem = await diaryDateActivityService.addGroupActivity(userToken, clubId, diaryDateId, groupId, activity);
+        const { clubId, diaryDateId, groupId, activity, timeblockId } = req.body;
+        const activityItem = await diaryDateActivityService.addGroupActivity(userToken, clubId, diaryDateId, groupId, activity, timeblockId);
         res.status(201).json(activityItem);        
     } catch (error) {
         devLog(error);
         res.status(500).json({ error: 'Error adding group activity' });
     }
+}
+
+export const deleteGroupActivity = async(req, res) => {
+    try {
+        const { authcode: userToken } = req.headers;
+        const { clubId, groupActivityId } = req.params;
+        await diaryDateActivityService.deleteGroupActivity(userToken, clubId, groupActivityId);
+        res.status(200).json({ message: 'Group activity deleted' });
+    } catch (error) {
+        devLog(error);
+        res.status(500).json({ error: 'Error deleting group activity' });
+    }
 }
\ No newline at end of file
diff --git a/backend/routes/diaryDateActivityRoutes.js b/backend/routes/diaryDateActivityRoutes.js
index 545e468..3f9ecc0 100644
--- a/backend/routes/diaryDateActivityRoutes.js
+++ b/backend/routes/diaryDateActivityRoutes.js
@@ -6,6 +6,7 @@ import {
     updateDiaryDateActivityOrder,
     getDiaryDateActivities,
     addGroupActivity,
+    deleteGroupActivity,
 } from '../controllers/diaryDateActivityController.js';
 import { authenticate } from '../middleware/authMiddleware.js';
 
@@ -14,6 +15,7 @@ const router = express.Router();
 router.use(authenticate);
 
 router.post('/group', addGroupActivity);
+router.delete('/group/:clubId/:groupActivityId', deleteGroupActivity);
 router.post('/:clubId/', createDiaryDateActivity);
 router.put('/:clubId/:id/order', updateDiaryDateActivityOrder);
 router.put('/:clubId/:id', updateDiaryDateActivity);
diff --git a/backend/services/diaryDateActivityService.js b/backend/services/diaryDateActivityService.js
index d63aa9a..f965c0f 100644
--- a/backend/services/diaryDateActivityService.js
+++ b/backend/services/diaryDateActivityService.js
@@ -231,16 +231,31 @@ class DiaryDateActivityService {
         return activitiesWithImages;
     }
 
-    async addGroupActivity(userToken, clubId, diaryDateId, groupId, activity) {
+    async addGroupActivity(userToken, clubId, diaryDateId, groupId, activity, timeblockId = null) {
         await checkAccess(userToken, clubId);
-        const diaryDateActivity = await DiaryDateActivity.findOne({
-            where: {
-                diaryDateId,
-                isTimeblock: true,
-            },
-            order: [['order_id', 'DESC']],
-            limit: 1
-        });
+        let diaryDateActivity;
+        
+        if (timeblockId) {
+            // Verwende die spezifische Zeitblock-ID, falls angegeben
+            diaryDateActivity = await DiaryDateActivity.findOne({
+                where: {
+                    id: timeblockId,
+                    diaryDateId,
+                    isTimeblock: true,
+                }
+            });
+        } else {
+            // Fallback: Verwende den letzten Zeitblock
+            diaryDateActivity = await DiaryDateActivity.findOne({
+                where: {
+                    diaryDateId,
+                    isTimeblock: true,
+                },
+                order: [['order_id', 'DESC']],
+                limit: 1
+            });
+        }
+        
         if (!diaryDateActivity) {
             console.error('[DiaryDateActivityService::addGroupActivity] Activity not found');
             throw new Error('Activity not found');
@@ -276,6 +291,15 @@ class DiaryDateActivityService {
         devLog(activityData);
         return await GroupActivity.create(activityData);
     }
+
+    async deleteGroupActivity(userToken, clubId, groupActivityId) {
+        await checkAccess(userToken, clubId);
+        const groupActivity = await GroupActivity.findByPk(groupActivityId);
+        if (!groupActivity) {
+            throw new Error('Group activity not found');
+        }
+        return await groupActivity.destroy();
+    }
 }
 
 export default new DiaryDateActivityService();
diff --git a/frontend/src/views/DiaryView.vue b/frontend/src/views/DiaryView.vue
index 91f94b5..67ed509 100644
--- a/frontend/src/views/DiaryView.vue
+++ b/frontend/src/views/DiaryView.vue
@@ -117,8 +117,7 @@
                                                         class="dropdown" style="max-height: 9.5em;">
                                                         <div v-for="s in editSearchResults" :key="s.id"
                                                             @click="chooseEditSuggestion(s, item)">
-                                                            <span v-if="s.code && s.code.trim() !== ''"><strong>[{{
-                                                                    s.name }}]</strong> </span>
+                                                            <span v-if="s.code && s.code.trim() !== ''"><strong>[{{ s.code }}]</strong> </span>{{ s.name }}
                                                         </div>
                                                     </div>
                                                 </div>
@@ -139,13 +138,28 @@
                                         </td>
                                         <td>{{ item.groupActivity ? item.groupActivity.name : '' }}</td>
                                         <td>
-                                            {{ item.duration }}<span
-                                                v-if="item.durationText && item.durationText.trim() !== ''"> ({{
-                                                    item.durationText }})</span>
+                                            <span v-if="editingActivityId === item.id">
+                                                <div style="display: flex; gap: 5px; align-items: center;">
+                                                    <input type="text" v-model="editingDurationText" 
+                                                        @input="calculateDurationForEdit"
+                                                        @keyup.enter="saveActivityEdit(item)"
+                                                        placeholder="z.B. 2x7" style="width: 80px;" />
+                                                    <input type="number" v-model="editingDuration" 
+                                                        @keyup.enter="saveActivityEdit(item)"
+                                                        style="width: 60px;" placeholder="Min" />
+                                                </div>
+                                            </span>
+                                            <span v-else class="clickable" @click="startActivityEdit(item)">
+                                                {{ item.duration || '' }}<span
+                                                    v-if="item.durationText && item.durationText.trim() !== ''"> ({{
+                                                        item.durationText }})</span>
+                                            </span>
                                         </td>
                                         <td>
                                             <button v-if="!item.isTimeblock" @click="toggleActivityMembers(item)" title="Teilnehmer zuordnen"
                                                 class="person-btn">👤</button>
+                                            <button v-if="item.isTimeblock" @click="addGroupActivityToTimeblock(item.id)" title="Gruppen-Aktivität hinzufügen"
+                                                class="btn-primary" style="font-size: 12px; padding: 2px 6px;">+ Gruppe</button>
                                             <button @click="removePlanItem(item.id)" class="trash-btn">🗑️</button>
                                             <div v-if="activityMembersOpenId === item.id" class="dropdown"
                                                 style="max-height: 12em; padding: 0.25rem;">
@@ -177,6 +191,35 @@
                                             </div>
                                         </td>
                                     </tr>
+                                    <!-- Formular zum Hinzufügen einer Gruppen-Aktivität direkt nach dem Zeitblock -->
+                                    <tr v-if="item.isTimeblock && addNewGroupActivity && selectedTimeblockId === item.id">
+                                        <td></td>
+                                        <td></td>
+                                        <td colspan="2">
+                                            <div style="display: flex; gap: 0.5rem; align-items: center; padding: 0.5rem; background: #f0f0f0; border-radius: 4px;">
+                                                <select v-model="newPlanItem.groupId" style="flex: 1;">
+                                                    <option value="">Gruppe auswählen...</option>
+                                                    <option v-for="group in groups" :key="group.id" :value="group.id">{{
+                                                        group.name }}</option>
+                                                </select>
+                                                <input type="text" v-model="newPlanItem.activity" placeholder="Aktivität" 
+                                                    @input="onNewItemInputChange" style="flex: 1;" />
+                                                <div v-if="newItemShowDropdown && newItemSearchResults.length"
+                                                    class="dropdown" style="max-height: 9.5em;">
+                                                    <div v-for="s in newItemSearchResults" :key="s.id"
+                                                        @click="chooseNewItemSuggestion(s)">
+                                                        <span v-if="s.code && s.code.trim() !== ''"><strong>[{{ s.code
+                                                                }}]</strong> </span>{{ s.name }}
+                                                    </div>
+                                                </div>
+                                            </div>
+                                        </td>
+                                        <td></td>
+                                        <td>
+                                            <span class="add-plan-item" @click="addPlanItem">+</span>
+                                            <span class="cancel" @click="cancelAddItem">X</span>
+                                        </td>
+                                    </tr>
                                     <template v-for="groupItem in item.groupActivities">
                                         <tr>
                                             <td></td>
@@ -201,6 +244,7 @@
                                             <td>
                                                 <button @click="toggleGroupActivityMembers(groupItem)" title="Teilnehmer zuordnen"
                                                     class="person-btn">👤</button>
+                                                <button @click="removeGroupActivity(groupItem.id)" class="trash-btn" title="Löschen">🗑️</button>
                                                 <div v-if="groupActivityMembersOpenId === groupItem.id" class="dropdown"
                                                     style="max-height: 12em; padding: 0.25rem;">
                                                     <div style="margin-bottom: 0.25rem; font-weight: 600; display: flex; align-items: center; gap: 0.5rem;">
@@ -270,10 +314,23 @@
                                     </td>
                                     <td v-else-if="addNewTimeblock">Zeitblock</td>
                                     <td v-if="addNewGroupActivity" colspan="2">
-                                        <select v-model="newPlanItem.groupId">
-                                            <option v-for="group in groups" :key="group.id" :value="group.id">{{
-                                                group.name }}</option>
-                                        </select>
+                                        <div style="display: flex; gap: 0.5rem; align-items: center;">
+                                            <select v-model="newPlanItem.groupId" style="flex: 1;">
+                                                <option value="">Gruppe auswählen...</option>
+                                                <option v-for="group in groups" :key="group.id" :value="group.id">{{
+                                                    group.name }}</option>
+                                            </select>
+                                            <input type="text" v-model="newPlanItem.activity" placeholder="Aktivität" 
+                                                @input="onNewItemInputChange" style="flex: 1;" />
+                                            <div v-if="newItemShowDropdown && newItemSearchResults.length"
+                                                class="dropdown" style="max-height: 9.5em;">
+                                                <div v-for="s in newItemSearchResults" :key="s.id"
+                                                    @click="chooseNewItemSuggestion(s)">
+                                                    <span v-if="s.code && s.code.trim() !== ''"><strong>[{{ s.code
+                                                            }}]</strong> </span>{{ s.name }}
+                                                </div>
+                                            </div>
+                                        </div>
                                     </td>
                                     <td v-else-if="addNewItem || addNewTimeblock"></td>
                                     <td v-if="(addNewItem || addNewTimeblock) && !addNewGroupActivity">
@@ -538,6 +595,7 @@ export default {
             renderModalData: null,
             groups: [],
             currentTimeBlockId: null,
+            selectedTimeblockId: null,
             newGroupCount: 2,
             addtype: 'activity',
             addNewItem: false,
@@ -573,6 +631,8 @@ export default {
             editSearchResults: [],
             editSearchForId: null,
             editingActivityText: '',
+            editingDuration: null,
+            editingDurationText: '',
             // Suche für Neue-Item-Eingabe
             newItemShowDropdown: false,
             newItemSearchResults: [],
@@ -1215,16 +1275,22 @@ export default {
                         orderId: this.trainingPlan.length
                     });
                 } else if (this.addNewGroupActivity) {
+                    if (!this.newPlanItem.groupId || !this.newPlanItem.activity) {
+                        this.showInfo('Hinweis', 'Bitte wählen Sie eine Gruppe und geben Sie eine Aktivität ein.', '', 'warning');
+                        return;
+                    }
                     await apiClient.post(`/diary-date-activities/group`, {
                         clubId: this.currentClub,
                         diaryDateId: this.date.id,
                         activity: this.newPlanItem.activity,
                         groupId: this.newPlanItem.groupId,
+                        timeblockId: this.selectedTimeblockId,
                     });
                 }
                 this.addNewTimeblock = false;
                 this.addNewItem = false;
                 this.addNewGroupActivity = false;
+                this.selectedTimeblockId = null;
                 this.newPlanItem = { activity: '', duration: '', durationText: '', groupId: '' };
                 this.trainingPlan = await apiClient.get(`/diary-date-activities/${this.currentClub}/${this.date.id}`).then(response => response.data);
                 this.calculateIntermediateTimes();
@@ -1354,6 +1420,22 @@ export default {
                 this.newPlanItem = { ...this.newPlanItem, duration: calculatedDuration };
             }
         },
+        calculateDurationForEdit() {
+            const input = this.editingDurationText;
+            let calculatedDuration = 0;
+            const multiplyPattern = /(\d+)\s*[x*]\s*(\d+)/i;
+            const match = input.match(multiplyPattern);
+            if (match) {
+                const [, num1, num2] = match;
+                calculatedDuration = parseInt(num1) * parseInt(num2);
+            } else if (!isNaN(input) && input.trim() !== '') {
+                calculatedDuration = parseInt(input);
+            }
+            if (calculatedDuration > 0) {
+                calculatedDuration = Math.ceil(calculatedDuration / 5) * 5;
+                this.editingDuration = calculatedDuration;
+            }
+        },
         async removePlanItem(planItemId) {
             try {
                 await apiClient.delete(`/diary-date-activities/${this.currentClub}/${planItemId}`);
@@ -1362,6 +1444,23 @@ export default {
                 this.showInfo('Fehler', 'Ein Fehler ist aufgetreten. Bitte versuchen Sie es erneut.', '', 'error');
             }
         },
+        async removeGroupActivity(groupActivityId) {
+            try {
+                await apiClient.delete(`/diary-date-activities/group/${this.currentClub}/${groupActivityId}`);
+                // Entferne die GroupActivity aus dem trainingPlan
+                for (const item of this.trainingPlan) {
+                    if (item.groupActivities) {
+                        const index = item.groupActivities.findIndex(ga => ga.id === groupActivityId);
+                        if (index !== -1) {
+                            item.groupActivities.splice(index, 1);
+                            break;
+                        }
+                    }
+                }
+            } catch (error) {
+                this.showInfo('Fehler', 'Ein Fehler ist aufgetreten. Bitte versuchen Sie es erneut.', '', 'error');
+            }
+        },
         async onDragEnd(evt) {
             const movedItem = this.trainingPlan[evt.oldIndex];
             try {
@@ -1502,6 +1601,7 @@ export default {
             this.addNewItem = false;
             this.addNewGroupActivity = false;
             this.addNewTimeblock = false;
+            this.selectedTimeblockId = null;
         },
         addTimeblock() {
             this.addNewTimeblock = true;
@@ -1512,6 +1612,13 @@ export default {
             this.addNewGroupActivity = true;
             this.addNewItem = false;
             this.addNewTimeblock = false;
+            this.selectedTimeblockId = null; // Verwende den letzten Zeitblock
+        },
+        addGroupActivityToTimeblock(timeblockId) {
+            this.addNewGroupActivity = true;
+            this.addNewItem = false;
+            this.addNewTimeblock = false;
+            this.selectedTimeblockId = timeblockId;
         },
         toggleShowGeneralData() {
             this.showGeneralData = !this.showGeneralData;
@@ -1708,17 +1815,23 @@ export default {
         startActivityEdit(item) {
             this.editingActivityId = item.id;
             this.$nextTick(() => {
-                this.$refs.activityInput.focus();
+                if (this.$refs.activityInput && this.$refs.activityInput[0]) {
+                    this.$refs.activityInput[0].focus();
+                } else if (this.$refs.activityInput) {
+                    this.$refs.activityInput.focus();
+                }
             });
             this.editingActivityText = item.predefinedActivity ? item.predefinedActivity.name : item.activity || '';
+            this.editingDuration = item.duration || null;
+            this.editingDurationText = item.durationText || '';
         },
 
         async saveActivityEdit(item) {
             try {
                 await apiClient.put(`/diary-date-activities/${this.currentClub}/${item.id}`, {
                     customActivityName: this.editingActivityText,
-                    duration: item.duration,
-                    durationText: item.durationText,
+                    duration: this.editingDuration || null,
+                    durationText: this.editingDurationText || null,
                     groupId: item.groupId,
                 });
 
@@ -1727,6 +1840,8 @@ export default {
 
                 this.editingActivityId = null;
                 this.editingActivityText = '';
+                this.editingDuration = null;
+                this.editingDurationText = '';
             } catch (error) {
                 this.showInfo('Fehler', 'Ein Fehler ist aufgetreten. Bitte versuchen Sie es erneut.', '', 'error');
             }
@@ -1839,6 +1954,9 @@ export default {
 
         cancelActivityEdit() {
             this.editingActivityId = null;
+            this.editingActivityText = '';
+            this.editingDuration = null;
+            this.editingDurationText = '';
         },
         toggleActivitiesBox() {
             this.showActivitiesBox = !this.showActivitiesBox;