diff --git a/app_new/gmao_config/routes.py b/app_new/gmao_config/routes.py
index c695af8..76ad727 100644
--- a/app_new/gmao_config/routes.py
+++ b/app_new/gmao_config/routes.py
@@ -8,7 +8,8 @@ from app_new.extensions import db
 from app_new.outlook.models import GmaoContext
 
 gmao_config_bp = Blueprint('gmao_config', __name__, template_folder='templates')
-LOOKBACK_MAX_HOURS = 24 * 365
+# Autoriser une synchronisation/analyse jusqu'à trois ans en arrière.
+LOOKBACK_MAX_HOURS = 24 * 365 * 3
 
 
 def _bounded_int(value, default, minimum=1, maximum=None):
diff --git a/app_new/gmao_config/templates/gmao_config/index.html b/app_new/gmao_config/templates/gmao_config/index.html
index c779871..8e794ea 100644
--- a/app_new/gmao_config/templates/gmao_config/index.html
+++ b/app_new/gmao_config/templates/gmao_config/index.html
@@ -250,7 +250,7 @@
                             </div>
                             <div class="col-md-4 mb-3">
                                 <label class="form-label">Lookback ENT / interprétation (heures)</label>
-                                <input type="number" name="auto_interpret_lookback_hours" class="form-control" min="1" max="8760"
+                                <input type="number" name="auto_interpret_lookback_hours" class="form-control" min="1" max="26280"
                                        value="{{ context.auto_interpret_lookback_hours or 24 }}">
                                 <small class="text-muted">Maximum : 8 760 heures (365 jours).</small>
                             </div>
@@ -307,7 +307,7 @@
                             </div>
                             <div class="col-md-6 mb-3">
                                 <label class="form-label">Lookback (heures)</label>
-                                <input type="number" name="outlook_sync_lookback_hours" class="form-control" min="1" max="8760"
+                                <input type="number" name="outlook_sync_lookback_hours" class="form-control" min="1" max="26280"
                                        value="{{ context.outlook_sync_lookback_hours or 24 }}">
                                 <small class="text-muted">Maximum : 8 760 heures (365 jours).</small>
                             </div>
diff --git a/app_new/templates/gmao_config/index.html b/app_new/templates/gmao_config/index.html
index c779871..8e794ea 100644
--- a/app_new/templates/gmao_config/index.html
+++ b/app_new/templates/gmao_config/index.html
@@ -250,7 +250,7 @@
                             </div>
                             <div class="col-md-4 mb-3">
                                 <label class="form-label">Lookback ENT / interprétation (heures)</label>
-                                <input type="number" name="auto_interpret_lookback_hours" class="form-control" min="1" max="8760"
+                                <input type="number" name="auto_interpret_lookback_hours" class="form-control" min="1" max="26280"
                                        value="{{ context.auto_interpret_lookback_hours or 24 }}">
                                 <small class="text-muted">Maximum : 8 760 heures (365 jours).</small>
                             </div>
@@ -307,7 +307,7 @@
                             </div>
                             <div class="col-md-6 mb-3">
                                 <label class="form-label">Lookback (heures)</label>
-                                <input type="number" name="outlook_sync_lookback_hours" class="form-control" min="1" max="8760"
+                                <input type="number" name="outlook_sync_lookback_hours" class="form-control" min="1" max="26280"
                                        value="{{ context.outlook_sync_lookback_hours or 24 }}">
                                 <small class="text-muted">Maximum : 8 760 heures (365 jours).</small>
                             </div>