diff --git a/loko/contracts/services_teams.py b/loko/contracts/services_teams.py
index 619bc99..b443ba1 100644
--- a/loko/contracts/services_teams.py
+++ b/loko/contracts/services_teams.py
@@ -141,25 +141,35 @@ def set_member_team_schedule(
                 Q(leave_date__isnull=True) | Q(leave_date__gte=target_date)
             ).update(leave_date=prev_leave)
 
+    # Trouver le prochain jalon futur pour cette équipe
+    next_hist = (
+        CompanyMemberHistory.objects
+        .filter(member=member, team_id=team_id, join_date__gt=target_date)
+        .order_by('join_date')
+        .first()
+    )
+    next_leave_bound = (next_hist.join_date - timedelta(days=1)) if next_hist else None
+
     # Vérifier s'il existe déjà un enregistrement pour cette équipe débutant à target_date
-    existing_hist = CompanyMemberHistory.objects.filter(
-        member=member,
-        team_id=team_id,
-        join_date=target_date,
-    ).first()
+    existing_hists = list(
+        CompanyMemberHistory.objects.filter(
+            member=member,
+            team_id=team_id,
+            join_date=target_date,
+        ).order_by('id')
+    )
 
-    if existing_hist:
-        new_history = existing_hist
+    if existing_hists:
+        new_history = existing_hists[0]
+        # Nettoyer les doublons éventuels
+        if len(existing_hists) > 1:
+            for extra in existing_hists[1:]:
+                extra.delete()
+        # S'assurer que leave_date est cohérent avec le prochain jalon futur
+        if new_history.leave_date != next_leave_bound:
+            new_history.leave_date = next_leave_bound
+            new_history.save(update_fields=['leave_date'])
     else:
-        # Trouver le prochain jalon futur pour cette équipe
-        next_hist = (
-            CompanyMemberHistory.objects
-            .filter(member=member, team_id=team_id, join_date__gt=target_date)
-            .order_by('join_date')
-            .first()
-        )
-        next_leave_bound = (next_hist.join_date - timedelta(days=1)) if next_hist else None
-
         new_history = CompanyMemberHistory.objects.create(
             member=member,
             team_id=team_id,
diff --git a/loko/contracts/signals.py b/loko/contracts/signals.py
index 04930d6..ffdfb78 100644
--- a/loko/contracts/signals.py
+++ b/loko/contracts/signals.py
@@ -45,6 +45,7 @@ def update_order_total_on_quote_item_delete(sender, instance, **kwargs):
     order.save(update_fields=['total_amount'])
 
 
+from django.db.models import Q
 from django.db.models.signals import m2m_changed
 from contracts.models import CompanyMember, CompanyMemberHistory
 from django.utils import timezone
@@ -57,44 +58,65 @@ def update_member_team_history(sender, instance, action, reverse, pk_set, **kwar
         # instance est CompanyMember, pk_set contient les team_id
         if action == "post_add" and pk_set:
             for team_id in pk_set:
-                CompanyMemberHistory.objects.get_or_create(
+                has_active = CompanyMemberHistory.objects.filter(
                     member=instance,
                     team_id=team_id,
-                    leave_date__isnull=True,
-                    defaults={'join_date': today}
-                )
+                    join_date__lte=today,
+                ).filter(
+                    Q(leave_date__isnull=True) | Q(leave_date__gte=today)
+                ).exists()
+                if not has_active:
+                    CompanyMemberHistory.objects.create(
+                        member=instance,
+                        team_id=team_id,
+                        join_date=today,
+                        leave_date=None,
+                    )
         elif action == "post_remove" and pk_set:
             for team_id in pk_set:
                 CompanyMemberHistory.objects.filter(
                     member=instance,
                     team_id=team_id,
-                    leave_date__isnull=True
+                    join_date__lte=today,
+                    leave_date__isnull=True,
                 ).update(leave_date=today)
         elif action == "pre_clear":
             CompanyMemberHistory.objects.filter(
                 member=instance,
-                leave_date__isnull=True
+                join_date__lte=today,
+                leave_date__isnull=True,
             ).update(leave_date=today)
     else:
         # instance est CompanyTeam, pk_set contient les member_id
         if action == "post_add" and pk_set:
             for member_id in pk_set:
-                CompanyMemberHistory.objects.get_or_create(
+                has_active = CompanyMemberHistory.objects.filter(
                     member_id=member_id,
                     team=instance,
-                    leave_date__isnull=True,
-                    defaults={'join_date': today}
-                )
+                    join_date__lte=today,
+                ).filter(
+                    Q(leave_date__isnull=True) | Q(leave_date__gte=today)
+                ).exists()
+                if not has_active:
+                    CompanyMemberHistory.objects.create(
+                        member_id=member_id,
+                        team=instance,
+                        join_date=today,
+                        leave_date=None,
+                    )
         elif action == "post_remove" and pk_set:
             for member_id in pk_set:
                 CompanyMemberHistory.objects.filter(
                     member_id=member_id,
                     team=instance,
-                    leave_date__isnull=True
+                    join_date__lte=today,
+                    leave_date__isnull=True,
                 ).update(leave_date=today)
         elif action == "pre_clear":
             CompanyMemberHistory.objects.filter(
                 team=instance,
-                leave_date__isnull=True
+                join_date__lte=today,
+                leave_date__isnull=True,
             ).update(leave_date=today)
 
+
diff --git a/loko/contracts/test_planning.py b/loko/contracts/test_planning.py
index 13f064e..80bc724 100644
--- a/loko/contracts/test_planning.py
+++ b/loko/contracts/test_planning.py
@@ -483,13 +483,81 @@ class TeamPlanningAjaxViewsTests(TestCase):
         self.assertEqual(self.member_alice.teams.count(), 1)
         self.assertEqual(self.member_alice.teams.first(), self.team_b)
 
-    def test_can_view_member_history_in_teams_views(self):
-        resp = self.client.get(reverse('contracts:teams_index'))
+    def test_m2m_signal_does_not_corrupt_future_histories(self):
+        """Vérifier que les signaux m2m_changed à aujourd'hui ne corrompent pas les historiques futurs."""
+        today = timezone.now().date()
+        future_date = today + timedelta(days=5)
+
+        member = CompanyMember.objects.create(name="Test Member", user=self.user)
+        # Créer une affectation future avec leave_date=None
+        future_hist = CompanyMemberHistory.objects.create(
+            member=member,
+            team=self.team_a,
+            join_date=future_date,
+            leave_date=None,
+        )
+
+        # Modifier les équipes du membre aujourd'hui (déclenche m2m_changed pre_clear / post_add)
+        member.teams.set([self.team_b])
+
+        future_hist.refresh_from_db()
+        # La leave_date de l'historique futur ne doit PAS avoir été écrasée par today !
+        self.assertIsNone(future_hist.leave_date)
+
+    def test_reproduce_and_fix_add_member_with_corrupted_leave_date(self):
+        """
+        Tester le scénario réel :
+        - Un membre a un historique existant au 14 avec leave_date antérieure (ex: corrupted 11).
+        - Un jalon au 15 existe.
+        - L'ajout via l'API AJAX doit réparer leave_date à 14 et faire apparaître le membre dans la modale et la composition.
+        """
+        today = timezone.now().date()
+        date_14 = today + timedelta(days=2)
+        date_15 = today + timedelta(days=3)
+
+        member_sebastien = CompanyMember.objects.create(name="Sébastien", user=self.user)
+        set_member_team_schedule(member_sebastien, self.team_a.id, date_14, action='move')
+
+        member_olivier = CompanyMember.objects.create(name="Olivier Buissette", user=self.user)
+        # Jalon au 15
+        CompanyMemberHistory.objects.create(
+            member=member_olivier,
+            team=self.team_a,
+            join_date=date_15,
+            leave_date=None,
+        )
+        # Historique corrompu au 14 (leave_date < join_date)
+        corrupted_hist = CompanyMemberHistory.objects.create(
+            member=member_olivier,
+            team=self.team_a,
+            join_date=date_14,
+            leave_date=today - timedelta(days=1),
+        )
+
+        # Avant : Olivier n'est pas dans la composition du 14 car leave_date < 14
+        comp_before = get_teams_composition_for_period({self.team_a.id}, date_14, date_14)
+        self.assertNotIn(member_olivier.id, [m['id'] for m in comp_before.get((self.team_a.id, date_14), [])])
+
+        # L'utilisateur l'ajoute le 14 via l'API AJAX
+        url = reverse('contracts:team_planning_assign_member_ajax')
+        resp = self.client.post(url, data=json.dumps({
+            'member_id': member_olivier.id,
+            'team_id': self.team_a.id,
+            'date': date_14.isoformat(),
+            'action': 'add',
+        }), content_type='application/json')
         self.assertEqual(resp.status_code, 200)
-        self.assertTrue(resp.context['can_view_member_history'])
 
-        data_resp = self.client.get(reverse('contracts:team_planning_data_ajax'))
-        self.assertEqual(data_resp.status_code, 200)
-        self.assertTrue(data_resp.json()['can_view_member_history'])
+        corrupted_hist.refresh_from_db()
+        # leave_date doit être réparée et bornée au 14 (date_15 - 1 jour)
+        self.assertEqual(corrupted_hist.leave_date, date_14)
+
+        # Vérifier dans l'API de composition journalière (modale)
+        url_modal = reverse('interventions:team_daily_members_ajax', args=[self.team_a.id])
+        resp_modal = self.client.get(url_modal, {'date': date_14.isoformat()})
+        self.assertEqual(resp_modal.status_code, 200)
+        modal_member_ids = [m['id'] for m in resp_modal.json()['current_members']]
+        self.assertIn(member_olivier.id, modal_member_ids)
+
 
 
diff --git a/loko/contracts/tests.py b/loko/contracts/tests.py
index 53147c2..8bf0da5 100644
--- a/loko/contracts/tests.py
+++ b/loko/contracts/tests.py
@@ -97,6 +97,9 @@ class TeamViewsAjaxTests(TestCase):
         
         self.member = CompanyMember.objects.create(name="Tech A", user=self.user)
         self.member.teams.add(self.team_a)
+        today = timezone.now().date()
+        yesterday = today - timezone.timedelta(days=1)
+        CompanyMemberHistory.objects.filter(member=self.member, team=self.team_a).update(join_date=yesterday)
 
     def test_teams_move_member_transfer(self):
         """Test moving a member transfers them (removes old, adds new)."""
@@ -119,8 +122,9 @@ class TeamViewsAjaxTests(TestCase):
         
         # Verify history was updated
         today = timezone.now().date()
+        yesterday = today - timezone.timedelta(days=1)
         h_old = CompanyMemberHistory.objects.get(member=self.member, team=self.team_a)
-        self.assertEqual(h_old.leave_date, today)
+        self.assertEqual(h_old.leave_date, yesterday)
         h_new = CompanyMemberHistory.objects.get(member=self.member, team=self.team_b)
         self.assertEqual(h_new.join_date, today)
         self.assertIsNone(h_new.leave_date)
diff --git a/loko/interventions/static/interventions/calendar/interventions_calendar.js b/loko/interventions/static/interventions/calendar/interventions_calendar.js
index db93f3b..08b80bb 100644
--- a/loko/interventions/static/interventions/calendar/interventions_calendar.js
+++ b/loko/interventions/static/interventions/calendar/interventions_calendar.js
@@ -5397,16 +5397,18 @@ function loadTeamDailyMembersModalData(teamId, dateStr) {
     const candidateSelect = document.getElementById('team-daily-candidate-select');
 
     let url;
+    const cacheBuster = `_t=${Date.now()}`;
     if (typeof teamDailyMembersUrlPattern !== 'undefined') {
-        url = teamDailyMembersUrlPattern.replace('/0/', `/${teamId}/`) + `?date=${encodeURIComponent(dateStr)}`;
+        url = teamDailyMembersUrlPattern.replace('/0/', `/${teamId}/`) + `?date=${encodeURIComponent(dateStr)}&${cacheBuster}`;
     } else if (typeof teamDailyMembersBaseUrl !== 'undefined') {
         const base = teamDailyMembersBaseUrl.replace(/\/members\/?$/, '/');
-        url = `${base.replace(/\/+$/, '')}/${teamId}/members/?date=${encodeURIComponent(dateStr)}`;
+        url = `${base.replace(/\/+$/, '')}/${teamId}/members/?date=${encodeURIComponent(dateStr)}&${cacheBuster}`;
     } else {
-        url = `/interventions/calendar/team/${teamId}/members/?date=${encodeURIComponent(dateStr)}`;
+        url = `/interventions/calendar/team/${teamId}/members/?date=${encodeURIComponent(dateStr)}&${cacheBuster}`;
     }
 
     fetch(url, {
+        cache: 'no-store',
         headers: { 'X-Requested-With': 'XMLHttpRequest' }
     })
     .then(res => {
diff --git a/loko/interventions/views/calendar.py b/loko/interventions/views/calendar.py
index 89bdb17..51f30dd 100644
--- a/loko/interventions/views/calendar.py
+++ b/loko/interventions/views/calendar.py
@@ -11,6 +11,7 @@ from django.contrib.gis.measure import D
 from django.contrib.contenttypes.models import ContentType
 from django.contrib import messages
 from django.views.decorators.http import require_POST, require_GET, require_http_methods
+from django.views.decorators.cache import never_cache
 from django.contrib.auth.decorators import login_required
 from django.utils.timezone import now, localtime, make_aware, get_current_timezone, is_naive
 from django.utils import timezone as django_timezone
@@ -990,18 +991,15 @@ def _interventions_events_by_teams_daily(
                     
             if not active:
                 continue
-                
-            if len(active) > 1:
-                # Resolve conflicts:
-                # Exclude those ending on day d if there is at least one that does not end on day d
-                non_ending = [h for h in active if h['leave_date'] != d]
-                if non_ending:
-                    active = non_ending
-            
-            # Add to team_compositions_sets for the remaining team(s)
+
+            # Grouper par équipe pour éliminer les doublons au sein d'une même équipe
+            active_by_team = defaultdict(list)
             for h in active:
-                team_compositions_sets[(h['team_id'], d)].add((m_id, member_name))
-                member_teams_by_day[d][m_id].add(h['team_id'])
+                active_by_team[h['team_id']].append(h)
+
+            for t_id in active_by_team.keys():
+                team_compositions_sets[(t_id, d)].add((m_id, member_name))
+                member_teams_by_day[d][m_id].add(t_id)
                 
     # 5.b Récupérer les absences pour cette semaine
     absences_map = {
@@ -1635,6 +1633,7 @@ def member_history_ajax(request, member_id):
     })
 
 
+@never_cache
 def team_daily_members_ajax(request, team_id):
     """
     Renvoie la composition d'une équipe à une date donnée, ainsi que les