diff --git a/api/README.md b/api/README.md
index 8941c79a2d46caeeb71189bed18aa8e9ba00451e..861524933d63c913f2d0bc10302d96e2e0741dfb 100644
--- a/api/README.md
+++ b/api/README.md
@@ -11,3 +11,9 @@ docker compose exec php bin/console doctrine:migrations:diff
 docker compose exec php bin/console doctrine:migrations:migrate
 ```
 
+(Optimisation)
+Indexation de la Colonne de Date, car toutes les routes font des opérations de filtrage basées sur cette colonne.
+````sql
+create index date_index on sale (date);
+````
+
diff --git a/api/composer.json b/api/composer.json
index eb987c7510418ba7b4c92e1785072c90a58bb6fb..812930e4ef38d7aa75643aa4aa8a6e4896b16db6 100644
--- a/api/composer.json
+++ b/api/composer.json
@@ -7,6 +7,7 @@
         "ext-iconv": "*",
         "api-platform/core": "^3.2",
         "beberlei/doctrineextensions": "dev-master",
+        "doctrine/cache": "*",
         "doctrine/doctrine-bundle": "^2.7",
         "doctrine/doctrine-migrations-bundle": "^3.2",
         "doctrine/orm": "^2.12",
diff --git a/api/composer.lock b/api/composer.lock
index 0663f0e9673f88c6dcd17383c5b7ef4deafed07f..f2a9d6ba930bc72d2efb09f3d3685fac6c4f4b5e 100644
--- a/api/composer.lock
+++ b/api/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "bd6b6c41a9c7342b985895c36f7ab96c",
+    "content-hash": "03c3d0b50d73e40d0c29a385e97c5c6c",
     "packages": [
         {
             "name": "api-platform/core",
diff --git a/api/src/Service/BarChartService.php b/api/src/Service/BarChartService.php
index efa52f8b842504ac9ce5f4a0c4fd22a41b5e089a..67b6ffa103de1ce0f030d42acfdabf0a780fcca7 100644
--- a/api/src/Service/BarChartService.php
+++ b/api/src/Service/BarChartService.php
@@ -28,44 +28,59 @@ class BarChartService
         $endDate = new \DateTime($input->end);
 
         $queryBuilder = $this->entityManager->createQueryBuilder();
+        $output = [];
 
-        switch ($input->granularity) {
-            case 'day':
-                $groupByExpression = 's.date';
-                $groupByAlias = 'date';
-                $dateFormat = 'Y-m-d';
-                break;
-            case 'month':
-                $groupByExpression = 'MONTH(s.date)';
-                $groupByAlias = 'month';
-                $dateFormat = 'Y-m';
-                break;
-            case 'year':
-                $groupByExpression = 'YEAR(s.date)';
-                $groupByAlias = 'year';
-                $dateFormat = 'Y';
-                break;
-            default:
-                throw new \InvalidArgumentException('Invalid granularity');
-        }
+        if($input->granularity == 'month'){
+            $result = $queryBuilder
+                ->select( 'YEAR(s.date) as year', 'MONTH(s.date) as month' ,'COUNT(s.id) as occurrences')
+                ->from(Sale::class, 's')
+                ->where('s.date BETWEEN :start AND :end')
+                ->setParameter('start', $startDate->format('Y-m-d'))
+                ->setParameter('end', $endDate->format('Y-m-d'))
+                ->groupBy("year","month")
+                ->orderBy("year")
+                ->getQuery()
+                ->getResult();
 
-        $result = $queryBuilder
-            ->select("{$groupByExpression} as {$groupByAlias}", 'COUNT(s.id) as occurrences')
-            ->from(Sale::class, 's')
-            ->where('s.date BETWEEN :start AND :end')
-            ->setParameter('start', $startDate->format('Y-m-d'))
-            ->setParameter('end', $endDate->format('Y-m-d'))
-            ->groupBy("{$groupByAlias}")
-            ->orderBy("{$groupByAlias}")
-            ->getQuery()
-            ->getResult();
+            foreach ($result as $row) {
+                $month = $row['month'];
+                $year = $row['year'];
+                $dateString = $year . '-' . str_pad($month, 2, '0', STR_PAD_LEFT);
+                $output[] = new BarChartOutput($dateString, (int)$row['occurrences']);
+            }
 
-        $output = [];
-        foreach ($result as $row) {
-            $dateString = $row[$groupByAlias] instanceof \DateTimeInterface ? $row[$groupByAlias]->format($dateFormat) : $row[$groupByAlias];
-            $output[] = new BarChartOutput($dateString, (int)$row['occurrences']);
-        }
+        } else
+        {
+            switch ($input->granularity) {
+                case 'day':
+                    $groupByExpression = 's.date';
+                    $groupByAlias = 'date';
+                    $dateFormat = 'Y-m-d';
+                    break;
+                case 'year':
+                    $groupByExpression = 'YEAR(s.date)';
+                    $groupByAlias = 'year';
+                    $dateFormat = 'Y';
+                    break;
+                default:
+                    throw new \InvalidArgumentException('Invalid granularity');
+            }
+            $result = $queryBuilder
+                ->select("{$groupByExpression} as {$groupByAlias}", 'COUNT(s.id) as occurrences')
+                ->from(Sale::class, 's')
+                ->where('s.date BETWEEN :start AND :end')
+                ->setParameter('start', $startDate->format('Y-m-d'))
+                ->setParameter('end', $endDate->format('Y-m-d'))
+                ->groupBy("{$groupByAlias}")
+                ->orderBy("{$groupByAlias}")
+                ->getQuery()
+                ->getResult();
 
+            foreach ($result as $row) {
+                $dateString = $row[$groupByAlias] instanceof \DateTimeInterface ? $row[$groupByAlias]->format($dateFormat) : $row[$groupByAlias];
+                $output[] = new BarChartOutput($dateString, (int)$row['occurrences']);
+            }
+        }
         return $output;
     }