diff --git a/melos.yaml b/melos.yaml
index f9c8130..728e20a 100644
--- a/melos.yaml
+++ b/melos.yaml
@@ -10,7 +10,7 @@ command:
 
 scripts:
   lint:all:
-    run: dart run melos run analyze && dart run melos run format-check
+    run: dart run melos run analyze && dart run melos run format-check && dart run melos run test
     description: Run all static analysis checks.
 
   get:
@@ -21,7 +21,6 @@ scripts:
   upgrade:
     run: melos exec -c 1 -- "flutter pub upgrade"
 
-
   analyze:
     run: |
       dart run melos exec -c 1 -- \
@@ -35,3 +34,9 @@ scripts:
   format-check:
     run: dart run melos exec dart format . --set-exit-if-changed
     description: Run `dart format` checks for all packages.
+
+  test:
+    run: |
+      dart run melos exec -c 1 -- \
+        flutter test -r github --no-test-assets
+    description: Run `flutter test` to validate all tests for all packages
diff --git a/packages/flutter_availability/lib/src/routes.dart b/packages/flutter_availability/lib/src/routes.dart
index 8fc7947..080daa2 100644
--- a/packages/flutter_availability/lib/src/routes.dart
+++ b/packages/flutter_availability/lib/src/routes.dart
@@ -1,5 +1,4 @@
 import "package:flutter/material.dart";
-import "package:flutter_availability/src/service/availability_service.dart";
 import "package:flutter_availability/src/ui/screens/availability_modification.dart";
 import "package:flutter_availability/src/ui/screens/availability_overview.dart";
 import "package:flutter_availability/src/ui/screens/template_day_modification.dart";
diff --git a/packages/flutter_availability/lib/src/ui/screens/availability_modification.dart b/packages/flutter_availability/lib/src/ui/screens/availability_modification.dart
index 15e0983..56fd389 100644
--- a/packages/flutter_availability/lib/src/ui/screens/availability_modification.dart
+++ b/packages/flutter_availability/lib/src/ui/screens/availability_modification.dart
@@ -1,6 +1,5 @@
 import "package:flutter/material.dart";
 import "package:flutter_availability/flutter_availability.dart";
-import "package:flutter_availability/src/service/availability_service.dart";
 import "package:flutter_availability/src/ui/view_models/availability_view_model.dart";
 import "package:flutter_availability/src/ui/view_models/break_view_model.dart";
 import "package:flutter_availability/src/ui/widgets/availability_clear.dart";
@@ -9,6 +8,7 @@ import "package:flutter_availability/src/ui/widgets/availabillity_time_selection
 import "package:flutter_availability/src/ui/widgets/base_page.dart";
 import "package:flutter_availability/src/ui/widgets/pause_selection.dart";
 import "package:flutter_availability/src/util/scope.dart";
+import "package:flutter_availability/src/util/utils.dart";
 import "package:flutter_hooks/flutter_hooks.dart";
 
 /// Screen for modifying the availabilities for a specific daterange
@@ -84,12 +84,12 @@ class _AvailabilitiesModificationScreenState
         if (_availabilityViewModel.templateSelected) {
           await service.applyTemplate(
             template: _availabilityViewModel.templates.first,
-            range: widget.dateRange,
+            range: widget.dateRange.toAvailabilityDateRange(),
           );
         } else {
           await service.createAvailability(
             availability: _availabilityViewModel.toModel(),
-            range: widget.dateRange,
+            range: widget.dateRange.toAvailabilityDateRange(),
           );
         }
         widget.onExit();
diff --git a/packages/flutter_availability/lib/src/ui/screens/availability_overview.dart b/packages/flutter_availability/lib/src/ui/screens/availability_overview.dart
index 5767ab3..b24fafe 100644
--- a/packages/flutter_availability/lib/src/ui/screens/availability_overview.dart
+++ b/packages/flutter_availability/lib/src/ui/screens/availability_overview.dart
@@ -1,9 +1,9 @@
 import "package:flutter/material.dart";
-import "package:flutter_availability/src/service/availability_service.dart";
 import "package:flutter_availability/src/ui/widgets/base_page.dart";
 import "package:flutter_availability/src/ui/widgets/calendar.dart";
 import "package:flutter_availability/src/ui/widgets/template_legend.dart";
 import "package:flutter_availability/src/util/scope.dart";
+import "package:flutter_availability_data_interface/flutter_availability_data_interface.dart";
 import "package:flutter_hooks/flutter_hooks.dart";
 
 ///
diff --git a/packages/flutter_availability/lib/src/ui/view_models/availability_view_model.dart b/packages/flutter_availability/lib/src/ui/view_models/availability_view_model.dart
index 172c6e7..392cd51 100644
--- a/packages/flutter_availability/lib/src/ui/view_models/availability_view_model.dart
+++ b/packages/flutter_availability/lib/src/ui/view_models/availability_view_model.dart
@@ -1,5 +1,4 @@
 import "package:flutter/material.dart";
-import "package:flutter_availability/src/service/availability_service.dart";
 import "package:flutter_availability/src/ui/view_models/break_view_model.dart";
 import "package:flutter_availability/src/util/utils.dart";
 import "package:flutter_availability_data_interface/flutter_availability_data_interface.dart";
diff --git a/packages/flutter_availability/lib/src/ui/widgets/calendar.dart b/packages/flutter_availability/lib/src/ui/widgets/calendar.dart
index d49c396..2a9dbcc 100644
--- a/packages/flutter_availability/lib/src/ui/widgets/calendar.dart
+++ b/packages/flutter_availability/lib/src/ui/widgets/calendar.dart
@@ -1,6 +1,5 @@
 import "package:flutter/material.dart";
-import "package:flutter_availability/src/config/availability_translations.dart";
-import "package:flutter_availability/src/service/availability_service.dart";
+import "package:flutter_availability/flutter_availability.dart";
 import "package:flutter_availability/src/ui/widgets/calendar_grid.dart";
 import "package:flutter_availability/src/util/availability_deviation.dart";
 import "package:flutter_availability/src/util/scope.dart";
diff --git a/packages/flutter_availability/lib/src/ui/widgets/pause_selection.dart b/packages/flutter_availability/lib/src/ui/widgets/pause_selection.dart
index c01f8a3..238a914 100644
--- a/packages/flutter_availability/lib/src/ui/widgets/pause_selection.dart
+++ b/packages/flutter_availability/lib/src/ui/widgets/pause_selection.dart
@@ -1,6 +1,5 @@
 import "package:flutter/material.dart";
 import "package:flutter_availability/flutter_availability.dart";
-import "package:flutter_availability/src/service/availability_service.dart";
 import "package:flutter_availability/src/service/pop_handler.dart";
 import "package:flutter_availability/src/ui/view_models/break_view_model.dart";
 import "package:flutter_availability/src/ui/widgets/generic_time_selection.dart";
diff --git a/packages/flutter_availability/lib/src/ui/widgets/template_legend.dart b/packages/flutter_availability/lib/src/ui/widgets/template_legend.dart
index beabcd2..aee25ac 100644
--- a/packages/flutter_availability/lib/src/ui/widgets/template_legend.dart
+++ b/packages/flutter_availability/lib/src/ui/widgets/template_legend.dart
@@ -1,6 +1,6 @@
 import "package:flutter/material.dart";
-import "package:flutter_availability/src/service/availability_service.dart";
 import "package:flutter_availability/src/util/scope.dart";
+import "package:flutter_availability_data_interface/flutter_availability_data_interface.dart";
 
 /// This shows all the templates of a given month and an option to navigate to
 /// the template overview
diff --git a/packages/flutter_availability/lib/src/userstories.dart b/packages/flutter_availability/lib/src/userstories.dart
index 88009d3..f1989e0 100644
--- a/packages/flutter_availability/lib/src/userstories.dart
+++ b/packages/flutter_availability/lib/src/userstories.dart
@@ -1,9 +1,9 @@
 import "package:flutter/material.dart";
 import "package:flutter_availability/src/config/availability_options.dart";
 import "package:flutter_availability/src/routes.dart";
-import "package:flutter_availability/src/service/availability_service.dart";
 import "package:flutter_availability/src/service/pop_handler.dart";
 import "package:flutter_availability/src/util/scope.dart";
+import "package:flutter_availability_data_interface/flutter_availability_data_interface.dart";
 
 /// This pushes the availability user story to the navigator stack.
 Future<void> openAvailabilitiesForUser(
diff --git a/packages/flutter_availability/lib/src/util/scope.dart b/packages/flutter_availability/lib/src/util/scope.dart
index f21ee00..a55bab8 100644
--- a/packages/flutter_availability/lib/src/util/scope.dart
+++ b/packages/flutter_availability/lib/src/util/scope.dart
@@ -1,7 +1,7 @@
 import "package:flutter/widgets.dart";
 import "package:flutter_availability/src/config/availability_options.dart";
-import "package:flutter_availability/src/service/availability_service.dart";
 import "package:flutter_availability/src/service/pop_handler.dart";
+import "package:flutter_availability_data_interface/flutter_availability_data_interface.dart";
 
 ///
 class AvailabilityScope extends InheritedWidget {
diff --git a/packages/flutter_availability/lib/src/util/utils.dart b/packages/flutter_availability/lib/src/util/utils.dart
index 4bdc655..fb5e808 100644
--- a/packages/flutter_availability/lib/src/util/utils.dart
+++ b/packages/flutter_availability/lib/src/util/utils.dart
@@ -1,4 +1,13 @@
+import "package:flutter/material.dart";
+import "package:flutter_availability/flutter_availability.dart";
+
 /// method to return if 2 dates are at the same time of the day
 /// ignoring the date
 bool isAtSameTime(DateTime date1, DateTime date2) =>
     date1.hour == date2.hour && date1.minute == date2.minute;
+
+/// extension to bridge between material and flutter agnostic dart package
+extension DateRangeConversion on DateTimeRange {
+  /// Creates a new [DateRange] given the internal [start] and [end] values.
+  DateRange toAvailabilityDateRange() => DateRange(start: start, end: end);
+}
diff --git a/packages/flutter_availability/pubspec.yaml b/packages/flutter_availability/pubspec.yaml
index 42b4655..da3282d 100644
--- a/packages/flutter_availability/pubspec.yaml
+++ b/packages/flutter_availability/pubspec.yaml
@@ -11,7 +11,6 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  rxdart: ^0.27.0
   flutter_hooks: ^0.20.5
   flutter_availability_data_interface:
     hosted: https://forgejo.internal.iconica.nl/api/packages/internal/pub
diff --git a/packages/flutter_availability_data_interface/lib/flutter_availability_data_interface.dart b/packages/flutter_availability_data_interface/lib/flutter_availability_data_interface.dart
index e02e28a..764f000 100644
--- a/packages/flutter_availability_data_interface/lib/flutter_availability_data_interface.dart
+++ b/packages/flutter_availability_data_interface/lib/flutter_availability_data_interface.dart
@@ -4,3 +4,5 @@ library flutter_availability_data_interface;
 export "src/data_interface.dart";
 export "src/models/availability.dart";
 export "src/models/templates.dart";
+export "src/service/availability_service.dart";
+export "src/utils/public.dart";
diff --git a/packages/flutter_availability_data_interface/lib/src/models/availability.dart b/packages/flutter_availability_data_interface/lib/src/models/availability.dart
index 46fd2ba..0981bb2 100644
--- a/packages/flutter_availability_data_interface/lib/src/models/availability.dart
+++ b/packages/flutter_availability_data_interface/lib/src/models/availability.dart
@@ -1,4 +1,4 @@
-import "package:flutter_availability_data_interface/src/utils.dart";
+import "package:flutter_availability_data_interface/src/utils/private.dart";
 
 /// Exception thrown when the end is before the start
 class BreakEndBeforeStartException implements Exception {}
diff --git a/packages/flutter_availability_data_interface/lib/src/models/templates.dart b/packages/flutter_availability_data_interface/lib/src/models/templates.dart
index 4cf9642..3774981 100644
--- a/packages/flutter_availability_data_interface/lib/src/models/templates.dart
+++ b/packages/flutter_availability_data_interface/lib/src/models/templates.dart
@@ -1,6 +1,6 @@
 import "package:flutter_availability_data_interface/flutter_availability_data_interface.dart";
 import "package:flutter_availability_data_interface/src/models/availability.dart";
-import "package:flutter_availability_data_interface/src/utils.dart";
+import "package:flutter_availability_data_interface/src/utils/private.dart";
 
 /// Exception thrown when the end is before the start
 class TemplateEndBeforeStartException implements Exception {}
diff --git a/packages/flutter_availability/lib/src/service/availability_service.dart b/packages/flutter_availability_data_interface/lib/src/service/availability_service.dart
similarity index 94%
rename from packages/flutter_availability/lib/src/service/availability_service.dart
rename to packages/flutter_availability_data_interface/lib/src/service/availability_service.dart
index 956d024..4c9ba9e 100644
--- a/packages/flutter_availability/lib/src/service/availability_service.dart
+++ b/packages/flutter_availability_data_interface/lib/src/service/availability_service.dart
@@ -1,5 +1,7 @@
-import "package:flutter/material.dart";
-import "package:flutter_availability_data_interface/flutter_availability_data_interface.dart";
+import "package:flutter_availability_data_interface/src/data_interface.dart";
+import "package:flutter_availability_data_interface/src/models/availability.dart";
+import "package:flutter_availability_data_interface/src/models/templates.dart";
+import "package:flutter_availability_data_interface/src/utils/public.dart";
 import "package:rxdart/rxdart.dart";
 
 ///
@@ -21,7 +23,7 @@ class AvailabilityService {
   /// changed
   Future<void> createAvailability({
     required AvailabilityModel availability,
-    required DateTimeRange range,
+    required DateRange range,
   }) async {
     // apply the startTime and endTime to the availability model
     var updatedAvailability = availability.copyWith(
@@ -68,7 +70,7 @@ class AvailabilityService {
   /// [template] to each day in the range
   Future<void> applyTemplate({
     required AvailabilityTemplateModel template,
-    required DateTimeRange range,
+    required DateRange range,
   }) async {
     await dataInterface.applyTemplateForUser(
       userId,
diff --git a/packages/flutter_availability_data_interface/lib/src/utils.dart b/packages/flutter_availability_data_interface/lib/src/utils/private.dart
similarity index 100%
rename from packages/flutter_availability_data_interface/lib/src/utils.dart
rename to packages/flutter_availability_data_interface/lib/src/utils/private.dart
diff --git a/packages/flutter_availability_data_interface/lib/src/utils/public.dart b/packages/flutter_availability_data_interface/lib/src/utils/public.dart
new file mode 100644
index 0000000..552cb07
--- /dev/null
+++ b/packages/flutter_availability_data_interface/lib/src/utils/public.dart
@@ -0,0 +1,14 @@
+/// Class that combines two dates
+class DateRange {
+  /// Construct the DateRange
+  const DateRange({
+    required this.start,
+    required this.end,
+  });
+
+  /// Start of the range
+  final DateTime start;
+
+  /// End of the range
+  final DateTime end;
+}
diff --git a/packages/flutter_availability_data_interface/pubspec.yaml b/packages/flutter_availability_data_interface/pubspec.yaml
index 41a7146..378b571 100644
--- a/packages/flutter_availability_data_interface/pubspec.yaml
+++ b/packages/flutter_availability_data_interface/pubspec.yaml
@@ -8,8 +8,12 @@ environment:
   sdk: ">=3.4.3 <4.0.0"
   flutter: ">=1.17.0"
 
+dependencies:
+  rxdart: ^0.27.0
+
 dev_dependencies:
   test: ^1.16.0
+  mocktail: ^1.0.4
   flutter_iconica_analysis:
     git:
       url: https://github.com/Iconica-Development/flutter_iconica_analysis
diff --git a/packages/flutter_availability_data_interface/test/mocks.dart b/packages/flutter_availability_data_interface/test/mocks.dart
new file mode 100644
index 0000000..f73eaad
--- /dev/null
+++ b/packages/flutter_availability_data_interface/test/mocks.dart
@@ -0,0 +1,8 @@
+import "package:flutter_availability_data_interface/flutter_availability_data_interface.dart";
+import "package:mocktail/mocktail.dart";
+
+class DataInterfaceMock extends Mock implements AvailabilityDataInterface {}
+
+class MockTemplate extends Mock implements AvailabilityTemplateModel {}
+
+class MockAvailability extends Mock implements AvailabilityModel {}
diff --git a/packages/flutter_availability/test/service/availability_service_test.dart b/packages/flutter_availability_data_interface/test/service/availability_service_test.dart
similarity index 95%
rename from packages/flutter_availability/test/service/availability_service_test.dart
rename to packages/flutter_availability_data_interface/test/service/availability_service_test.dart
index 43b9266..d10c376 100644
--- a/packages/flutter_availability/test/service/availability_service_test.dart
+++ b/packages/flutter_availability_data_interface/test/service/availability_service_test.dart
@@ -1,6 +1,6 @@
-import "package:flutter_availability/src/service/availability_service.dart";
-import "package:flutter_test/flutter_test.dart";
+import "package:flutter_availability_data_interface/src/service/availability_service.dart";
 import "package:mocktail/mocktail.dart";
+import "package:test/test.dart";
 
 import "../mocks.dart";