add intl package

lib/main.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:intl/date_symbol_data_local.dart';
 import 'package:provider/provider.dart';
 import 'package:smoke_cess_app/pages/main_page.dart';
 import 'package:smoke_cess_app/providers/tasks_provider.dart';
@@ -14,6 +15,7 @@ void main() {
   //init database
   globals.databaseService;
   tz.initializeTimeZones();
+  initializeDateFormatting('de');
   NotificationService().initNotification();
   runApp(const MyApp());
 }

pubspec.yaml

@@ -24,6 +24,7 @@ dependencies:
   http: ^0.13.5
   syncfusion_flutter_charts: ^20.4.52
   cupertino_icons: ^1.0.2
+  intl: ^0.18.0
 
 dev_dependencies:
   flutter_test: