diff --git a/app/lib/account.dart b/app/lib/account.dart
index c8c31298..dc830f2f 100644
--- a/app/lib/account.dart
+++ b/app/lib/account.dart
@@ -1,5 +1,6 @@
 import 'dart:math';
 
+import 'package:clock/clock.dart';
 import 'package:equatable/equatable.dart';
 import 'package:flutter/foundation.dart';
 import 'package:logging/logging.dart';
@@ -52,7 +53,7 @@ class Account with EquatableMixin {
   }
 
   static String newId() {
-    final timestamp = DateTime.now().millisecondsSinceEpoch;
+    final timestamp = clock.now().millisecondsSinceEpoch;
     final random = Random().nextInt(0xFFFFFF);
     return "${timestamp.toRadixString(16)}-${random.toRadixString(16).padLeft(6, '0')}";
   }
diff --git a/app/lib/api/api_util.dart b/app/lib/api/api_util.dart
index f025d17c..69e45bcf 100644
--- a/app/lib/api/api_util.dart
+++ b/app/lib/api/api_util.dart
@@ -1,6 +1,7 @@
 /// Helper functions working with remote Nextcloud server
 import 'dart:convert';
 
+import 'package:clock/clock.dart';
 import 'package:flutter/foundation.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/account.dart';
@@ -193,13 +194,13 @@ class InitiateLoginResponse {
 class InitiateLoginPollOptions {
   InitiateLoginPollOptions(this.token, String endpoint)
       : endpoint = Uri.parse(endpoint),
-        _validUntil = DateTime.now().add(const Duration(minutes: 20));
+        _validUntil = clock.now().add(const Duration(minutes: 20));
 
   @override
   String toString() => _$toString();
 
   bool isTokenValid() {
-    return DateTime.now().isBefore(_validUntil);
+    return clock.now().isBefore(_validUntil);
   }
 
   @Format(r"${kDebugMode ? $? : '***'}")
diff --git a/app/lib/entity/album.dart b/app/lib/entity/album.dart
index 2c69ba31..e85835a1 100644
--- a/app/lib/entity/album.dart
+++ b/app/lib/entity/album.dart
@@ -1,3 +1,4 @@
+import 'package:clock/clock.dart';
 import 'package:equatable/equatable.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/account.dart';
@@ -35,7 +36,7 @@ class Album with EquatableMixin {
     this.shares,
     this.albumFile,
     int? savedVersion,
-  })  : lastUpdated = (lastUpdated ?? DateTime.now()).toUtc(),
+  })  : lastUpdated = (lastUpdated ?? clock.now()).toUtc(),
         savedVersion = savedVersion ?? version;
 
   static Album? fromJson(
@@ -227,7 +228,7 @@ class AlbumShare with EquatableMixin {
     required this.userId,
     this.displayName,
     DateTime? sharedAt,
-  }) : sharedAt = (sharedAt ?? DateTime.now()).toUtc();
+  }) : sharedAt = (sharedAt ?? clock.now()).toUtc();
 
   factory AlbumShare.fromJson(JsonObj json) {
     return AlbumShare(
diff --git a/app/lib/entity/album/data_source.dart b/app/lib/entity/album/data_source.dart
index eb85b617..37de0c96 100644
--- a/app/lib/entity/album/data_source.dart
+++ b/app/lib/entity/album/data_source.dart
@@ -1,6 +1,7 @@
 import 'dart:convert';
 import 'dart:math';
 
+import 'package:clock/clock.dart';
 import 'package:drift/drift.dart' as sql;
 import 'package:kiwi/kiwi.dart';
 import 'package:logging/logging.dart';
@@ -94,7 +95,7 @@ class AlbumRemoteDataSource implements AlbumDataSource {
 
   String _makeAlbumFileName() {
     // just make up something
-    final timestamp = DateTime.now().millisecondsSinceEpoch;
+    final timestamp = clock.now().millisecondsSinceEpoch;
     final random = Random().nextInt(0xFFFFFF);
     return "${timestamp.toRadixString(16)}-${random.toRadixString(16).padLeft(6, '0')}.nc_album.json";
   }
diff --git a/app/lib/entity/file.dart b/app/lib/entity/file.dart
index f5603df9..56a2aef3 100644
--- a/app/lib/entity/file.dart
+++ b/app/lib/entity/file.dart
@@ -1,5 +1,6 @@
 import 'dart:typed_data';
 
+import 'package:clock/clock.dart';
 import 'package:equatable/equatable.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/account.dart';
@@ -93,7 +94,7 @@ class Metadata with EquatableMixin {
     this.imageWidth,
     this.imageHeight,
     this.exif,
-  }) : lastUpdated = (lastUpdated ?? DateTime.now()).toUtc();
+  }) : lastUpdated = (lastUpdated ?? clock.now()).toUtc();
 
   @override
   // ignore: hash_and_equals
diff --git a/app/lib/entity/file_util.dart b/app/lib/entity/file_util.dart
index acf23c90..5741c3ca 100644
--- a/app/lib/entity/file_util.dart
+++ b/app/lib/entity/file_util.dart
@@ -1,3 +1,4 @@
+import 'package:clock/clock.dart';
 import 'package:nc_photos/account.dart';
 import 'package:nc_photos/api/api_util.dart' as api_util;
 import 'package:nc_photos/entity/file.dart';
@@ -100,7 +101,8 @@ DateTime getBestDateTime({
   DateTime? overrideDateTime,
   DateTime? dateTimeOriginal,
   DateTime? lastModified,
-}) => overrideDateTime ?? dateTimeOriginal ?? lastModified ?? DateTime.now().toUtc();
+}) =>
+    overrideDateTime ?? dateTimeOriginal ?? lastModified ?? clock.now().toUtc();
 
 final supportedFormatMimes = [
   "image/jpeg",
diff --git a/app/lib/share_handler.dart b/app/lib/share_handler.dart
index a517078a..4a7b82a6 100644
--- a/app/lib/share_handler.dart
+++ b/app/lib/share_handler.dart
@@ -1,6 +1,7 @@
 import 'dart:async';
 import 'dart:math';
 
+import 'package:clock/clock.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:kiwi/kiwi.dart';
@@ -317,7 +318,7 @@ class ShareHandler {
       FileRepo fileRepo, Account account, String name) async {
     // add a intermediate dir to allow shared dirs having the same name. Since
     // the dir names are public, we can't add random pre/suffix
-    final timestamp = DateTime.now().millisecondsSinceEpoch;
+    final timestamp = clock.now().millisecondsSinceEpoch;
     final random = Random().nextInt(0xFFFFFF);
     final dirName =
         "${timestamp.toRadixString(16)}-${random.toRadixString(16).padLeft(6, "0")}";
diff --git a/app/lib/use_case/list_potential_shared_album.dart b/app/lib/use_case/list_potential_shared_album.dart
index 35da903c..674ec53b 100644
--- a/app/lib/use_case/list_potential_shared_album.dart
+++ b/app/lib/use_case/list_potential_shared_album.dart
@@ -1,3 +1,4 @@
+import 'package:clock/clock.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/account.dart';
 import 'package:nc_photos/entity/file.dart';
@@ -44,7 +45,7 @@ class ListPotentialSharedAlbum {
       final timestamp = int.parse(match.group(1)!, radix: 16);
       final time = DateTime.fromMillisecondsSinceEpoch(timestamp);
       _log.fine("[_checkFileName] Timestamp: $time");
-      if (time.isAfter(DateTime.now())) {
+      if (time.isAfter(clock.now())) {
         _log.warning("[_checkFileName] Invalid timestamp: ${f.path}");
         return false;
       }
diff --git a/app/lib/use_case/populate_album.dart b/app/lib/use_case/populate_album.dart
index 0815f79e..6d2d5b24 100644
--- a/app/lib/use_case/populate_album.dart
+++ b/app/lib/use_case/populate_album.dart
@@ -1,3 +1,4 @@
+import 'package:clock/clock.dart';
 import 'package:kiwi/kiwi.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/account.dart';
@@ -56,7 +57,7 @@ class PopulateAlbum {
         }
         products.addAll((result as List).cast<File>().map((f) => AlbumFileItem(
               addedBy: account.userId,
-              addedAt: DateTime.now(),
+              addedAt: clock.now(),
               file: f,
             )));
       }
@@ -73,7 +74,7 @@ class PopulateAlbum {
     final files = await ListTaggedFile(c)(account, provider.tags);
     products.addAll(files.map((f) => AlbumFileItem(
           addedBy: account.userId,
-          addedAt: DateTime.now(),
+          addedAt: clock.now(),
           file: f,
         )));
     return products;
@@ -93,7 +94,7 @@ class PopulateAlbum {
         .where((f) => file_util.isSupportedFormat(f))
         .map((f) => AlbumFileItem(
               addedBy: account.userId,
-              addedAt: DateTime.now(),
+              addedAt: clock.now(),
               file: f,
             ))
         .toList();
diff --git a/app/lib/widget/album_browser.dart b/app/lib/widget/album_browser.dart
index e973529e..30b62c26 100644
--- a/app/lib/widget/album_browser.dart
+++ b/app/lib/widget/album_browser.dart
@@ -1,5 +1,6 @@
 import 'dart:async';
 
+import 'package:clock/clock.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_staggered_grid_view/flutter_staggered_grid_view.dart';
@@ -670,7 +671,7 @@ class _AlbumBrowserState extends State<AlbumBrowser>
           items: [
             AlbumLabelItem(
               addedBy: widget.account.userId,
-              addedAt: DateTime.now(),
+              addedAt: clock.now(),
               text: value,
             ),
             ..._sortedItems,
diff --git a/app/lib/widget/builder/photo_list_item_builder.dart b/app/lib/widget/builder/photo_list_item_builder.dart
index 4d07be59..738a4eac 100644
--- a/app/lib/widget/builder/photo_list_item_builder.dart
+++ b/app/lib/widget/builder/photo_list_item_builder.dart
@@ -1,3 +1,4 @@
+import 'package:clock/clock.dart';
 import 'package:collection/collection.dart';
 import 'package:flutter/widgets.dart';
 import 'package:logging/logging.dart';
@@ -134,7 +135,7 @@ class _PhotoListItemBuilder {
 
   PhotoListItemBuilderResult _fromSortedItems(
       Account account, List<FileDescriptor> files) {
-    final today = DateTime.now();
+    final today = clock.now();
     final memoryAlbumHelper = smartAlbumConfig != null
         ? MemoryAlbumHelper(
             today: today, dayRange: smartAlbumConfig!.memoriesDayRange)
diff --git a/app/lib/widget/handler/add_selection_to_album_handler.dart b/app/lib/widget/handler/add_selection_to_album_handler.dart
index 00cb26fa..2c0d9c2a 100644
--- a/app/lib/widget/handler/add_selection_to_album_handler.dart
+++ b/app/lib/widget/handler/add_selection_to_album_handler.dart
@@ -1,3 +1,4 @@
+import 'package:clock/clock.dart';
 import 'package:flutter/material.dart';
 import 'package:kiwi/kiwi.dart';
 import 'package:logging/logging.dart';
@@ -48,7 +49,7 @@ class AddSelectionToAlbumHandler {
           final selected = selectedFiles
               .map((f) => AlbumFileItem(
                     addedBy: account.userId,
-                    addedAt: DateTime.now(),
+                    addedAt: clock.now(),
                     file: f,
                   ))
               .toList();
diff --git a/app/lib/widget/handler/double_tap_exit_handler.dart b/app/lib/widget/handler/double_tap_exit_handler.dart
index be47198b..26d9a8cf 100644
--- a/app/lib/widget/handler/double_tap_exit_handler.dart
+++ b/app/lib/widget/handler/double_tap_exit_handler.dart
@@ -1,3 +1,4 @@
+import 'package:clock/clock.dart';
 import 'package:flutter/material.dart';
 import 'package:nc_photos/app_localizations.dart';
 import 'package:nc_photos/k.dart' as k;
@@ -14,7 +15,7 @@ class DoubleTapExitHandler {
     if (!Pref().isDoubleTapExitOr()) {
       return true;
     }
-    final now = DateTime.now().toUtc();
+    final now = clock.now().toUtc();
     _lastBackButtonAt ??= now.subtract(const Duration(days: 1));
     if (now.difference(_lastBackButtonAt!) < const Duration(seconds: 5)) {
       return true;
diff --git a/app/lib/widget/photo_list_util.dart b/app/lib/widget/photo_list_util.dart
index f2d2df8a..0bbf2b69 100644
--- a/app/lib/widget/photo_list_util.dart
+++ b/app/lib/widget/photo_list_util.dart
@@ -1,5 +1,6 @@
 import 'dart:math' as math;
 
+import 'package:clock/clock.dart';
 import 'package:collection/collection.dart';
 import 'package:logging/logging.dart';
 import 'package:nc_photos/date_time_extension.dart';
@@ -41,7 +42,7 @@ class MemoryAlbumHelper {
   MemoryAlbumHelper({
     DateTime? today,
     required int dayRange,
-  })  : today = (today?.toLocal() ?? DateTime.now()).toMidnight(),
+  })  : today = (today?.toLocal() ?? clock.now()).toMidnight(),
         dayRange = math.max(dayRange, 0);
 
   void addFile(FileDescriptor f) {
diff --git a/app/lib/widget/splash.dart b/app/lib/widget/splash.dart
index ae94868a..8c8978f6 100644
--- a/app/lib/widget/splash.dart
+++ b/app/lib/widget/splash.dart
@@ -1,5 +1,6 @@
 import 'dart:async';
 
+import 'package:clock/clock.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:kiwi/kiwi.dart';
@@ -46,7 +47,7 @@ class _SplashState extends State<Splash> {
 
   Future<void> _doWork() async {
     if (Pref().getFirstRunTime() == null) {
-      await Pref().setFirstRunTime(DateTime.now().millisecondsSinceEpoch);
+      await Pref().setFirstRunTime(clock.now().millisecondsSinceEpoch);
     }
     if (_shouldUpgrade()) {
       setState(() {
diff --git a/app/pubspec.lock b/app/pubspec.lock
index 5386bf42..c0f8243b 100644
--- a/app/pubspec.lock
+++ b/app/pubspec.lock
@@ -228,7 +228,7 @@ packages:
     source: hosted
     version: "0.3.5"
   clock:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: clock
       url: "https://pub.dartlang.org"
diff --git a/app/pubspec.yaml b/app/pubspec.yaml
index e380fae0..55b1b962 100644
--- a/app/pubspec.yaml
+++ b/app/pubspec.yaml
@@ -38,6 +38,7 @@ dependencies:
   bloc_concurrency: ^0.2.0
   cached_network_image: ^3.2.1
   circular_reveal_animation: ^2.0.1
+  clock: ^1.1.1
   collection: ^1.15.0
   connectivity_plus: ^2.0.2
   copy_with:
diff --git a/app/test/entity/file_test.dart b/app/test/entity/file_test.dart
index 03bade8c..4202aa1a 100644
--- a/app/test/entity/file_test.dart
+++ b/app/test/entity/file_test.dart
@@ -1,3 +1,4 @@
+import 'package:clock/clock.dart';
 import 'package:nc_photos/entity/exif.dart';
 import 'package:nc_photos/entity/file.dart';
 import 'package:nc_photos/entity/file_descriptor.dart';
@@ -837,7 +838,7 @@ void main() {
       });
 
       test("lastModified", () {
-        final now = DateTime.now();
+        final now = clock.now();
         final file = src.copyWith(lastModified: now);
         expect(
             file,
@@ -1022,7 +1023,7 @@ void main() {
       });
 
       test("trashbinDeletionTime", () {
-        final now = DateTime.now();
+        final now = clock.now();
         final file = src.copyWith(trashbinDeletionTime: now);
         expect(
             file,
diff --git a/app/test/use_case/inflate_file_descriptor_test.dart b/app/test/use_case/inflate_file_descriptor_test.dart
index 02d0097f..2e409ad7 100644
--- a/app/test/use_case/inflate_file_descriptor_test.dart
+++ b/app/test/use_case/inflate_file_descriptor_test.dart
@@ -1,3 +1,4 @@
+import 'package:clock/clock.dart';
 import 'package:nc_photos/di_container.dart';
 import 'package:nc_photos/entity/file_descriptor.dart';
 import 'package:nc_photos/entity/sqlite/database.dart' as sql;
@@ -104,7 +105,7 @@ Future<void> _missing() async {
           fdMime: null,
           fdIsArchived: false,
           fdIsFavorite: false,
-          fdDateTime: DateTime.now(),
+          fdDateTime: clock.now(),
         ),
       ],
     ),