diff --git a/Dockerfile b/Dockerfile
index bddb5d6..218a767 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM php:8.2-cli
+FROM php:8.2-cli as base
 
 # Install system dependencies
 RUN apt-get update && apt-get install -y \
@@ -21,14 +21,15 @@ RUN curl -sS https://get.symfony.com/cli/installer | bash && \
 # Set working directory
 WORKDIR /var/www/html
 
+CMD ["symfony", "serve", "--port=8000", "--no-tls", "--allow-http", "--allow-all-ip"]
+
+FROM base as production
+
 # Copy application files
 COPY . .
 
 # Install dependencies
 RUN composer install --no-interaction --optimize-autoloader
 
-# Expose port
-EXPOSE 8000
-
 # Command to run Symfony server
 CMD ["symfony", "serve", "--port=8000", "--no-tls", "--allow-http", "--allow-all-ip"]
diff --git a/docker-compose.server.yml b/docker-compose.server.yml
index 378a0fa..a0df609 100644
--- a/docker-compose.server.yml
+++ b/docker-compose.server.yml
@@ -5,8 +5,9 @@ services:
     build:
       context: .
       dockerfile: Dockerfile
+      target: production
     environment:
-      - APP_ENV=dev
+      - APP_ENV=prod
       - APP_DEBUG=1
     networks:
       - proxy
diff --git a/docker-compose.yml b/docker-compose.yml
index 12ba59c..b214a46 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -3,6 +3,11 @@ services:
     build:
       context: .
       dockerfile: Dockerfile
+      target: base
+    ports:
+      - 8000:8000
     environment:
       - APP_ENV=dev
-      - APP_DEBUG=1
\ No newline at end of file
+      - APP_DEBUG=1
+    volumes:
+      - ./:/var/www/html
diff --git a/src/Controller/CalendarController.php b/src/Controller/CalendarController.php
index 1426853..7cec465 100644
--- a/src/Controller/CalendarController.php
+++ b/src/Controller/CalendarController.php
@@ -2,10 +2,12 @@
 
 namespace App\Controller;
 
+use App\HomeAssistant\HomeAssistantClient;
 use App\Service\AbsenceManager;
 use App\Service\CalendarExportService;
 use App\Service\CalendarService;
 use DateTime;
+use DateTimeImmutable;
 use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
@@ -17,6 +19,7 @@ final class CalendarController extends AbstractController
         private readonly AbsenceManager $absenceManager,
         private readonly CalendarService $calendarService,
         private readonly CalendarExportService $calendarExportService,
+        private readonly HomeAssistantClient $homeAssistantClient,
         private readonly string $requiredApiKey
     ) {
     }
@@ -57,12 +60,18 @@ final class CalendarController extends AbstractController
         
         $days = $this->calendarService->getAllDays($startDate, $endDate);
         $days = $this->calendarService->processAbsences($days, $absences);
+
+        $entityHistory = $this->homeAssistantClient->getEntityStateHistory(
+            'person.tim',
+            new DateTimeImmutable('-1 year'),
+            new DateTimeImmutable('+180 days')
+        );
         
-        $icsContent = $this->calendarExportService->generateIcsContent($days, $absences);
+        $icsContent = $this->calendarExportService->generateIcsContent($days, $entityHistory, $absences);
         
         $response = new Response($icsContent);
-        $response->headers->set('Content-Type', 'text/calendar; charset=utf-8');
-        $response->headers->set('Content-Disposition', 'attachment; filename="work_calendar.ics"');
+        //$response->headers->set('Content-Type', 'text/calendar; charset=utf-8');
+        //$response->headers->set('Content-Disposition', 'attachment; filename="work_calendar.ics"');
         
         return $response;
     }
diff --git a/src/HomeAssistant/HomeAssistantClient.php b/src/HomeAssistant/HomeAssistantClient.php
index 145f23d..a79d4e5 100644
--- a/src/HomeAssistant/HomeAssistantClient.php
+++ b/src/HomeAssistant/HomeAssistantClient.php
@@ -46,7 +46,7 @@ final readonly class HomeAssistantClient
             'filter_entity_id' => $entityId,
         ]);
 
-        return $this->request('GET', "/api/history/period/{$startDate->format('Y-m-d\TH:i:s\Z')}?{$queryParams}");
+        return $this->request('GET', "/api/history/period/{$startDate->format('Y-m-d\TH:i:s\Z')}?{$queryParams}")[0];
     }
 
     public function callService(string $domain, string $service, array $data = []): array
diff --git a/src/Service/CalendarExportService.php b/src/Service/CalendarExportService.php
index edb513a..1172772 100644
--- a/src/Service/CalendarExportService.php
+++ b/src/Service/CalendarExportService.php
@@ -14,7 +14,6 @@ final class CalendarExportService
     private const KAMEN_ADDRESS = 'Privat \nHeidkamp 21\n59174 Kamen\nDeutschland';
     private const COMPANY_NAME = 'CHECK24';
     private const TIMEZONE = 'Europe/Berlin';
-    private const PERSON_ENTITY = 'person.tim';
     private const OFFICE_STATE = 'CHECK24';
 
     public function __construct(
@@ -22,7 +21,7 @@ final class CalendarExportService
     ) {
     }
 
-    public function generateIcsContent(array $days, array $absences): string
+    public function generateIcsContent(array $days, array $entityHistory, array $absences): string
     {
         $icsContent = [
             'BEGIN:VCALENDAR',
@@ -39,7 +38,14 @@ final class CalendarExportService
             }
 
             $dayDate = clone $day['date'];
-            $startAndEndTimes = $this->getWorkTimesFromHomeAssistant($dayDate);
+            $startOfDay = DateTimeImmutable::createFromInterface($dayDate)->setTime(0, 0, 0);
+            $typicalEndOfDay = DateTimeImmutable::createFromInterface($dayDate)->setTime(17, 30, 0);
+        
+            $filteredEntityHistory = array_filter($entityHistory, function (array $state) use ($startOfDay, $typicalEndOfDay) {
+                return $state['last_changed'] >= $startOfDay && $state['last_changed'] <= $typicalEndOfDay;
+            });
+
+            $startAndEndTimes = $this->getWorkTimesFromHomeAssistant($filteredEntityHistory, $dayDate);
             
             if ($startAndEndTimes === null) {
                 $eventStart = clone $day['date'];
@@ -74,17 +80,9 @@ final class CalendarExportService
         return implode("\r\n", $icsContent);
     }
 
-    private function getWorkTimesFromHomeAssistant(DateTimeInterface $date): ?array
+    private function getWorkTimesFromHomeAssistant(array $stateHistory, DateTimeInterface $date): ?array
     {
-        $startOfDay = DateTimeImmutable::createFromInterface($date)->setTime(0, 0, 0);
-        $typicalEndOfDay = DateTimeImmutable::createFromInterface($date)->setTime(17, 30, 0);
-        
         try {
-            $stateHistory = $this->homeAssistantClient->getEntityStateHistory(
-                self::PERSON_ENTITY,
-                $startOfDay, 
-                $typicalEndOfDay
-            );
             
             if (empty($stateHistory) || empty($stateHistory[0])) {
                 return null;
diff --git a/src/Service/CalendarStorageService.php b/src/Service/CalendarStorageService.php
new file mode 100644
index 0000000..d859351
--- /dev/null
+++ b/src/Service/CalendarStorageService.php
@@ -0,0 +1,73 @@
+<?php
+
+namespace App\Service;
+
+use DateTime;
+use RuntimeException;
+
+final class CalendarStorageService
+{
+    private const STORAGE_FILE = 'storage/past_events.json';
+
+    /**
+     * Store past events in the storage file
+     */
+    public function storePastEvents(array $events): void
+    {
+        $dataDirectory = dirname(self::STORAGE_FILE);
+        
+        if (!is_dir($dataDirectory)) {
+            if (mkdir($dataDirectory, 0777, true) === false) {
+                throw new RuntimeException('Failed to create storage directory');
+            }
+        }
+        
+        if (file_put_contents(self::STORAGE_FILE, json_encode($events)) === false) {
+            throw new RuntimeException('Failed to write past events to storage file');
+        }
+    }
+
+    /**
+     * Get past events from the storage file
+     */
+    public function getPastEvents(): array
+    {
+        if (!file_exists(self::STORAGE_FILE)) {
+            return [];
+        }
+        
+        $content = file_get_contents(self::STORAGE_FILE);
+        
+        if ($content === false) {
+            return [];
+        }
+        
+        $events = json_decode($content, true);
+        
+        if (json_last_error() !== JSON_ERROR_NONE) {
+            return [];
+        }
+        
+        return $events;
+    }
+
+    /**
+     * Check if past events need to be updated by comparing with cutoff date
+     */
+    public function shouldUpdatePastEvents(DateTime $cutoffDate): bool
+    {
+        if (!file_exists(self::STORAGE_FILE)) {
+            return true;
+        }
+        
+        $fileModTime = filemtime(self::STORAGE_FILE);
+        
+        if ($fileModTime === false) {
+            return true;
+        }
+        
+        $fileModDate = (new DateTime())->setTimestamp($fileModTime);
+        
+        return $fileModDate < $cutoffDate;
+    }
+} 
\ No newline at end of file