diff --git a/lib/service/date_service.dart b/lib/service/date_service.dart
new file mode 100644
index 0000000..be45fe6
--- /dev/null
+++ b/lib/service/date_service.dart
@@ -0,0 +1,57 @@
+import 'package:smoke_cess_app/service/settings_service.dart';
+import 'package:timezone/timezone.dart';
+
+const int trainingTime = 40;
+
+const weekDays = {
+  "Montag": 1,
+  "Dienstag": 2,
+  "Mittwoch": 3,
+  "Donnerstag": 4,
+  "Freitag": 5,
+  "Samstag": 6,
+  "Sonntag": 7,
+};
+
+Future<List<TZDateTime>> getDatesforAll() async {
+  List<TZDateTime> allDates = [];
+  List<TZDateTime> moodDates = await getDatesforMood();
+  List<TZDateTime> sleepDates = await getDatesforSleep();
+  allDates.addAll(moodDates);
+  allDates.addAll(sleepDates);
+  return allDates;
+}
+
+Future<List<TZDateTime>> getDatesforMood() async {
+  final List<String>? selectedDays = await getMoodQueryDaysCategories();
+  final int? selectedHours = await getMoodQueryHours();
+  final int? selectedMinutes = await getMoodQueryMinutes();
+  return createTZDateTimes(selectedDays, selectedHours, selectedMinutes);
+}
+
+Future<List<TZDateTime>> getDatesforSleep() async {
+  final List<String>? selectedDays = await getSleepQueryDaysCategories();
+  final int? selectedHours = await getSleepQueryHours();
+  final int? selectedMinutes = await getSleepQueryMinutes();
+  return createTZDateTimes(selectedDays, selectedHours, selectedMinutes);
+}
+
+List<TZDateTime> createTZDateTimes(
+    List<String>? selectedDays, int? selectedHours, int? selectedMinutes) {
+  List<TZDateTime> tzDateTimes = [];
+  if (selectedDays == null ||
+      selectedHours == null ||
+      selectedMinutes == null) {
+    return tzDateTimes;
+  }
+  final Iterable<int?> selectedDaysInt =
+      selectedDays.map((day) => weekDays[day]);
+  for (int i = 0; i < trainingTime; i++) {
+    final DateTime date = DateTime.now().add(Duration(days: i));
+    if (selectedDaysInt.contains(date.weekday)) {
+      tzDateTimes.add(TZDateTime.local(date.year, date.month, date.day,
+          selectedHours, selectedMinutes, 0, 0, 0));
+    }
+  }
+  return tzDateTimes;
+}