diff --git a/mnemo_cards_backend/lib/database/database.dart b/mnemo_cards_backend/lib/database/database.dart
index 57ecf9f..f222448 100644
--- a/mnemo_cards_backend/lib/database/database.dart
+++ b/mnemo_cards_backend/lib/database/database.dart
@@ -32,6 +32,7 @@ import 'daos/promo_code_dao.dart';
 import 'daos/discount_dao.dart';
 import 'daos/statistics_dao.dart';
 import 'daos/achievement_dao.dart';
+import 'postgres_constants.dart';
 
 // Сгенерированный код будет здесь
 part 'database.g.dart';
diff --git a/mnemo_cards_backend/lib/database/database.g.dart b/mnemo_cards_backend/lib/database/database.g.dart
index ecbce88..3255287 100644
--- a/mnemo_cards_backend/lib/database/database.g.dart
+++ b/mnemo_cards_backend/lib/database/database.g.dart
@@ -92,7 +92,7 @@ class $UsersTable extends Users with TableInfo<$UsersTable, User> {
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -104,7 +104,7 @@ class $UsersTable extends Users with TableInfo<$UsersTable, User> {
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _isDeletedMeta = const VerificationMeta(
     'isDeleted',
@@ -723,7 +723,7 @@ class $UserDatasTable extends UserDatas
         false,
         type: DriftSqlType.dateTime,
         requiredDuringInsert: false,
-        defaultValue: currentDateAndTime,
+        defaultValue: currentTimestamp,
       );
   static const VerificationMeta _lastTestSessionTokenMeta =
       const VerificationMeta('lastTestSessionToken');
@@ -809,7 +809,7 @@ class $UserDatasTable extends UserDatas
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -821,7 +821,7 @@ class $UserDatasTable extends UserDatas
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -1720,7 +1720,7 @@ class $TokensTable extends Tokens with TableInfo<$TokensTable, Token> {
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _expiresMeta = const VerificationMeta(
     'expires',
@@ -2135,7 +2135,7 @@ class $RefreshTokensTable extends RefreshTokens
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _expiresAtMeta = const VerificationMeta(
     'expiresAt',
@@ -2586,7 +2586,7 @@ class $TelegramAuthCodesTable extends TelegramAuthCodes
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _expiresAtMeta = const VerificationMeta(
     'expiresAt',
@@ -3285,7 +3285,7 @@ class $CardPacksTable extends CardPacks
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -3297,7 +3297,7 @@ class $CardPacksTable extends CardPacks
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _isDeletedMeta = const VerificationMeta(
     'isDeleted',
@@ -4267,7 +4267,7 @@ class $GameCardsTable extends GameCards
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -4279,7 +4279,7 @@ class $GameCardsTable extends GameCards
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _isDeletedMeta = const VerificationMeta(
     'isDeleted',
@@ -4973,7 +4973,7 @@ class $VoiceModelsTable extends VoiceModels
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -5312,7 +5312,7 @@ class $UserPacksTable extends UserPacks
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _grantTypeMeta = const VerificationMeta(
     'grantType',
@@ -6431,7 +6431,7 @@ class $SubscriptionPlansTable extends SubscriptionPlans
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -6443,7 +6443,7 @@ class $SubscriptionPlansTable extends SubscriptionPlans
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _isDeletedMeta = const VerificationMeta(
     'isDeleted',
@@ -7062,7 +7062,7 @@ class $UserSubscriptionsTable extends UserSubscriptions
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -7074,7 +7074,7 @@ class $UserSubscriptionsTable extends UserSubscriptions
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -7541,7 +7541,7 @@ class $PaymentsTable extends Payments with TableInfo<$PaymentsTable, Payment> {
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   late final GeneratedColumnWithTypeConverter<List<dynamic>, String> products =
@@ -7588,7 +7588,7 @@ class $PaymentsTable extends Payments with TableInfo<$PaymentsTable, Payment> {
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -7600,7 +7600,7 @@ class $PaymentsTable extends Payments with TableInfo<$PaymentsTable, Payment> {
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -8332,7 +8332,7 @@ class $TestsTable extends Tests with TableInfo<$TestsTable, Test> {
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -8344,7 +8344,7 @@ class $TestsTable extends Tests with TableInfo<$TestsTable, Test> {
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _isDeletedMeta = const VerificationMeta(
     'isDeleted',
@@ -8909,7 +8909,7 @@ class $TestQuestionsTable extends TestQuestions
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -8921,7 +8921,7 @@ class $TestQuestionsTable extends TestQuestions
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -9540,7 +9540,7 @@ class $TestStatisticsTable extends TestStatistics
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _createdAtMeta = const VerificationMeta(
     'createdAt',
@@ -9552,7 +9552,7 @@ class $TestStatisticsTable extends TestStatistics
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -9564,7 +9564,7 @@ class $TestStatisticsTable extends TestStatistics
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -10056,7 +10056,7 @@ class $TasksTable extends Tasks with TableInfo<$TasksTable, Task> {
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -10068,7 +10068,7 @@ class $TasksTable extends Tasks with TableInfo<$TasksTable, Task> {
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -10712,7 +10712,7 @@ class $UserTasksTable extends UserTasks
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _expiresAtMeta = const VerificationMeta(
     'expiresAt',
@@ -10789,7 +10789,7 @@ class $UserTasksTable extends UserTasks
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -11545,7 +11545,7 @@ class $UserTaskProgressesTable extends UserTaskProgresses
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -11557,7 +11557,7 @@ class $UserTaskProgressesTable extends UserTaskProgresses
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -11956,7 +11956,7 @@ class $UserTaskResultsTable extends UserTaskResults
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _createdAtMeta = const VerificationMeta(
     'createdAt',
@@ -11968,7 +11968,7 @@ class $UserTaskResultsTable extends UserTaskResults
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -12436,7 +12436,7 @@ class $PromoCodesCampaignsTable extends PromoCodesCampaigns
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -12448,7 +12448,7 @@ class $PromoCodesCampaignsTable extends PromoCodesCampaigns
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _isDeletedMeta = const VerificationMeta(
     'isDeleted',
@@ -13189,7 +13189,7 @@ class $PromoCodesTable extends PromoCodes
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -13201,7 +13201,7 @@ class $PromoCodesTable extends PromoCodes
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -13654,7 +13654,7 @@ class $DiscountCampaignsTable extends DiscountCampaigns
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -13666,7 +13666,7 @@ class $DiscountCampaignsTable extends DiscountCampaigns
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _isDeletedMeta = const VerificationMeta(
     'isDeleted',
@@ -14191,7 +14191,7 @@ class $DiscountsTable extends Discounts
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -14203,7 +14203,7 @@ class $DiscountsTable extends Discounts
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _isDeletedMeta = const VerificationMeta(
     'isDeleted',
@@ -14642,7 +14642,7 @@ class $DiscountUserDatasTable extends DiscountUserDatas
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [discountId, userId, grantedAt];
@@ -15000,7 +15000,7 @@ class $StudySessionsTable extends StudySessions
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -15012,7 +15012,7 @@ class $StudySessionsTable extends StudySessions
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -15627,7 +15627,7 @@ class $UserAchievementsTable extends UserAchievements
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _progressMeta = const VerificationMeta(
     'progress',
@@ -15651,7 +15651,7 @@ class $UserAchievementsTable extends UserAchievements
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -15663,7 +15663,7 @@ class $UserAchievementsTable extends UserAchievements
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
@@ -16099,7 +16099,7 @@ class $ShareRequestsTable extends ShareRequests
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _createdAtMeta = const VerificationMeta(
     'createdAt',
@@ -16111,7 +16111,7 @@ class $ShareRequestsTable extends ShareRequests
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   static const VerificationMeta _updatedAtMeta = const VerificationMeta(
     'updatedAt',
@@ -16123,7 +16123,7 @@ class $ShareRequestsTable extends ShareRequests
     false,
     type: DriftSqlType.dateTime,
     requiredDuringInsert: false,
-    defaultValue: currentDateAndTime,
+    defaultValue: currentTimestamp,
   );
   @override
   List<GeneratedColumn> get $columns => [
diff --git a/mnemo_cards_backend/lib/database/postgres_constants.dart b/mnemo_cards_backend/lib/database/postgres_constants.dart
new file mode 100644
index 0000000..1195f29
--- /dev/null
+++ b/mnemo_cards_backend/lib/database/postgres_constants.dart
@@ -0,0 +1,5 @@
+import 'package:drift/drift.dart';
+
+/// PostgreSQL-совместимое выражение для текущей даты и времени
+/// Используется вместо currentDateAndTime, который использует SQLite-специфичную функцию strftime
+const Expression<DateTime> currentTimestamp = CustomExpression<DateTime>('NOW()');
diff --git a/mnemo_cards_backend/lib/database/tables/achievements.dart b/mnemo_cards_backend/lib/database/tables/achievements.dart
index 6f3f715..bf3a673 100644
--- a/mnemo_cards_backend/lib/database/tables/achievements.dart
+++ b/mnemo_cards_backend/lib/database/tables/achievements.dart
@@ -1,4 +1,5 @@
 import 'package:drift/drift.dart';
+import '../postgres_constants.dart';
 import 'users.dart';
 
 /// Таблица UserAchievements - достижения пользователей
@@ -11,14 +12,14 @@ class UserAchievements extends Table {
   TextColumn get achievementId => text()();
 
   // When achievement was unlocked
-  DateTimeColumn get unlockedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get unlockedAt => dateTime().withDefault(currentTimestamp)();
 
   // Progress (0.0 to 1.0)
   RealColumn get progress => real().withDefault(const Constant(1.0))();
 
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
 
   @override
   Set<Column> get primaryKey => {id};
diff --git a/mnemo_cards_backend/lib/database/tables/auth.dart b/mnemo_cards_backend/lib/database/tables/auth.dart
index d383272..45df2ff 100644
--- a/mnemo_cards_backend/lib/database/tables/auth.dart
+++ b/mnemo_cards_backend/lib/database/tables/auth.dart
@@ -1,6 +1,7 @@
 import 'package:drift/drift.dart';
 import 'users.dart';
 import '../converters.dart' show generateUuid;
+import '../postgres_constants.dart';
 
 /// Таблица Tokens - токены авторизации пользователей
 class Tokens extends Table {
@@ -10,7 +11,7 @@ class Tokens extends Table {
   TextColumn get token => text().unique()();
   TextColumn get externalUserId => text()();
   
-  DateTimeColumn get created => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get created => dateTime().withDefault(currentTimestamp)();
   DateTimeColumn get expires => dateTime()();
   
   @override
@@ -31,7 +32,7 @@ class RefreshTokens extends Table {
   
   BoolColumn get isBlacklisted => boolean().withDefault(const Constant(false))();
   
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
   DateTimeColumn get expiresAt => dateTime()();
   
   @override
@@ -51,7 +52,7 @@ class TelegramAuthCodes extends Table {
   BoolColumn get isUsed => boolean().withDefault(const Constant(false))();
   DateTimeColumn get usedAt => dateTime().nullable()();
   
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
   DateTimeColumn get expiresAt => dateTime()();
   
   @override
diff --git a/mnemo_cards_backend/lib/database/tables/discounts.dart b/mnemo_cards_backend/lib/database/tables/discounts.dart
index 87c2c54..6a2bede 100644
--- a/mnemo_cards_backend/lib/database/tables/discounts.dart
+++ b/mnemo_cards_backend/lib/database/tables/discounts.dart
@@ -1,5 +1,6 @@
 import 'package:drift/drift.dart';
 import '../converters.dart' show generateUuid, StringListConverter, JsonListConverter;
+import '../postgres_constants.dart';
 import 'users.dart';
 
 /// Таблица DiscountCampaigns - кампании скидок
@@ -20,8 +21,8 @@ class DiscountCampaigns extends Table {
       .map(const StringListConverter())();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   BoolColumn get isDeleted => boolean().withDefault(const Constant(false))();
   
   @override
@@ -42,8 +43,8 @@ class Discounts extends Table {
       .map(const JsonListConverter())();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   BoolColumn get isDeleted => boolean().withDefault(const Constant(false))();
   
   @override
@@ -55,7 +56,7 @@ class DiscountUserDatas extends Table {
   TextColumn get discountId => text().references(Discounts, #id, onDelete: KeyAction.cascade)();
   TextColumn get userId => text().references(Users, #id, onDelete: KeyAction.cascade)();
   
-  DateTimeColumn get grantedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get grantedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {discountId, userId};
diff --git a/mnemo_cards_backend/lib/database/tables/packs.dart b/mnemo_cards_backend/lib/database/tables/packs.dart
index 1c91c7b..da485a6 100644
--- a/mnemo_cards_backend/lib/database/tables/packs.dart
+++ b/mnemo_cards_backend/lib/database/tables/packs.dart
@@ -1,5 +1,6 @@
 import 'package:drift/drift.dart';
 import '../converters.dart' show generateUuid, IntListConverter, StringListConverter;
+import '../postgres_constants.dart';
 
 /// Таблица CardPacks - наборы карточек
 class CardPacks extends Table {
@@ -35,8 +36,8 @@ class CardPacks extends Table {
   TextColumn get currency => text().withDefault(const Constant('RUB'))();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   BoolColumn get isDeleted => boolean().withDefault(const Constant(false))();
   
   @override
@@ -65,8 +66,8 @@ class GameCards extends Table {
   TextColumn get back => text().nullable()();  // дополнительный текст
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   BoolColumn get isDeleted => boolean().withDefault(const Constant(false))();
   
   @override
@@ -81,7 +82,7 @@ class VoiceModels extends Table {
   TextColumn get voiceUrl => text()();  // URL аудиофайла
   TextColumn get language => text()();  // язык озвучки
 
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
diff --git a/mnemo_cards_backend/lib/database/tables/payments.dart b/mnemo_cards_backend/lib/database/tables/payments.dart
index 33ff7e2..02fff4f 100644
--- a/mnemo_cards_backend/lib/database/tables/payments.dart
+++ b/mnemo_cards_backend/lib/database/tables/payments.dart
@@ -1,5 +1,6 @@
 import 'package:drift/drift.dart';
 import '../converters.dart' show generateUuid, JsonListConverter, StringListConverter;
+import '../postgres_constants.dart';
 import 'users.dart';
 
 /// Таблица Payments - платежи
@@ -17,7 +18,7 @@ class Payments extends Table {
   TextColumn get externalToken => text().nullable()();
   TextColumn get meta => text().nullable()();
   
-  DateTimeColumn get date => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get date => dateTime().withDefault(currentTimestamp)();
   
   // Продукты (JSON array)
   TextColumn get products => text()
@@ -31,8 +32,8 @@ class Payments extends Table {
   BoolColumn get subscription => boolean().withDefault(const Constant(false))();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
diff --git a/mnemo_cards_backend/lib/database/tables/promo_codes.dart b/mnemo_cards_backend/lib/database/tables/promo_codes.dart
index de52c84..c9424bc 100644
--- a/mnemo_cards_backend/lib/database/tables/promo_codes.dart
+++ b/mnemo_cards_backend/lib/database/tables/promo_codes.dart
@@ -1,5 +1,6 @@
 import 'package:drift/drift.dart';
 import '../converters.dart' show generateUuid, JsonListConverter, StringListConverter;
+import '../postgres_constants.dart';
 import 'users.dart';
 
 /// Таблица PromoCodesCampaigns - кампании промокодов
@@ -30,8 +31,8 @@ class PromoCodesCampaigns extends Table {
       .map(const StringListConverter())();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   BoolColumn get isDeleted => boolean().withDefault(const Constant(false))();
   
   @override
@@ -50,8 +51,8 @@ class PromoCodes extends Table {
   TextColumn get userId => text().nullable().references(Users, #id, onDelete: KeyAction.cascade)();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
diff --git a/mnemo_cards_backend/lib/database/tables/relations.dart b/mnemo_cards_backend/lib/database/tables/relations.dart
index fa399e2..fb43291 100644
--- a/mnemo_cards_backend/lib/database/tables/relations.dart
+++ b/mnemo_cards_backend/lib/database/tables/relations.dart
@@ -1,4 +1,5 @@
 import 'package:drift/drift.dart';
+import '../postgres_constants.dart';
 import 'users.dart';
 import 'packs.dart' show CardPacks, GameCards, VoiceModels;
 
@@ -9,7 +10,7 @@ class UserPacks extends Table {
   TextColumn get packId => text().references(CardPacks, #id, onDelete: KeyAction.cascade)();
   
   // Когда пользователь получил доступ к паку
-  DateTimeColumn get grantedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get grantedAt => dateTime().withDefault(currentTimestamp)();
   
   // Как пользователь получил пак (purchase, promo, free, admin)
   TextColumn get grantType => text().withDefault(const Constant('purchase'))();
diff --git a/mnemo_cards_backend/lib/database/tables/statistics.dart b/mnemo_cards_backend/lib/database/tables/statistics.dart
index 145885f..5420a3c 100644
--- a/mnemo_cards_backend/lib/database/tables/statistics.dart
+++ b/mnemo_cards_backend/lib/database/tables/statistics.dart
@@ -1,6 +1,7 @@
 import 'package:drift/drift.dart';
 import 'users.dart';
 import '../converters.dart' show generateUuid;
+import '../postgres_constants.dart';
 
 /// Таблица StudySessions - сессии изучения
 class StudySessions extends Table {
@@ -20,8 +21,8 @@ class StudySessions extends Table {
   TextColumn get testId => text().nullable()();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
diff --git a/mnemo_cards_backend/lib/database/tables/subscriptions.dart b/mnemo_cards_backend/lib/database/tables/subscriptions.dart
index 7447725..cab6194 100644
--- a/mnemo_cards_backend/lib/database/tables/subscriptions.dart
+++ b/mnemo_cards_backend/lib/database/tables/subscriptions.dart
@@ -1,6 +1,7 @@
 import 'package:drift/drift.dart';
 
 import '../converters.dart' show JsonMapConverter, JsonListConverter;
+import '../postgres_constants.dart';
 import 'users.dart';
 
 /// Таблица SubscriptionPlans - планы подписки
@@ -25,8 +26,8 @@ class SubscriptionPlans extends Table {
   TextColumn get paymentSystem => text()();  // enum as string
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   BoolColumn get isDeleted => boolean().withDefault(const Constant(false))();
   
   @override
@@ -47,8 +48,8 @@ class UserSubscriptions extends Table {
       .map(const JsonListConverter())();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
diff --git a/mnemo_cards_backend/lib/database/tables/tasks.dart b/mnemo_cards_backend/lib/database/tables/tasks.dart
index fc99034..28642b5 100644
--- a/mnemo_cards_backend/lib/database/tables/tasks.dart
+++ b/mnemo_cards_backend/lib/database/tables/tasks.dart
@@ -1,5 +1,6 @@
 import 'package:drift/drift.dart';
 import '../converters.dart' show generateUuid, JsonListConverter, JsonMapConverter, StringListConverter;
+import '../postgres_constants.dart';
 import 'users.dart';
 
 /// Таблица Tasks - задачи системы
@@ -17,8 +18,8 @@ class Tasks extends Table {
   DateTimeColumn get lastExecution => dateTime().nullable()();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
@@ -39,7 +40,7 @@ class UserTasks extends Table {
       .withDefault(const Constant('[]'))
       .map(const JsonListConverter())();
   
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
   DateTimeColumn get expiresAt => dateTime()();
   DateTimeColumn get completedAt => dateTime().nullable()();
   
@@ -54,7 +55,7 @@ class UserTasks extends Table {
   TextColumn get imageUrl => text().nullable()();
   
   // Audit
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
@@ -71,8 +72,8 @@ class UserTaskProgresses extends Table {
       .withDefault(const Constant('{}'))
       .map(const JsonMapConverter())();
 
-  DateTimeColumn get startedAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get startedAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
@@ -89,10 +90,10 @@ class UserTaskResults extends Table {
       .withDefault(const Constant('{}'))
       .map(const JsonMapConverter())();
   
-  DateTimeColumn get completedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get completedAt => dateTime().withDefault(currentTimestamp)();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
diff --git a/mnemo_cards_backend/lib/database/tables/telegram.dart b/mnemo_cards_backend/lib/database/tables/telegram.dart
index e2acafa..fdcd58f 100644
--- a/mnemo_cards_backend/lib/database/tables/telegram.dart
+++ b/mnemo_cards_backend/lib/database/tables/telegram.dart
@@ -1,5 +1,6 @@
 import 'package:drift/drift.dart';
 import '../converters.dart' show generateUuid;
+import '../postgres_constants.dart';
 
 /// Таблица ShareRequests - запросы на шаринг через Telegram
 class ShareRequests extends Table {
@@ -10,11 +11,11 @@ class ShareRequests extends Table {
   
   TextColumn get sharedCardId => text().nullable()();
   
-  DateTimeColumn get requestedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get requestedAt => dateTime().withDefault(currentTimestamp)();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
diff --git a/mnemo_cards_backend/lib/database/tables/tests.dart b/mnemo_cards_backend/lib/database/tables/tests.dart
index 9dc55f8..e2cc527 100644
--- a/mnemo_cards_backend/lib/database/tables/tests.dart
+++ b/mnemo_cards_backend/lib/database/tables/tests.dart
@@ -1,5 +1,6 @@
 import 'package:drift/drift.dart';
 import '../converters.dart' show generateUuid, JsonMapConverter;
+import '../postgres_constants.dart';
 import 'packs.dart';
 
 /// Таблица Tests - тесты
@@ -14,8 +15,8 @@ class Tests extends Table {
   TextColumn get timeSubtitle => text().nullable()();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   BoolColumn get isDeleted => boolean().withDefault(const Constant(false))();
   
   @override
@@ -32,8 +33,8 @@ class TestQuestions extends Table {
   TextColumn get body => text()();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
@@ -59,11 +60,11 @@ class TestStatistics extends Table {
       .withDefault(const Constant('{}'))
       .map(const JsonMapConverter())();
   
-  DateTimeColumn get completedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get completedAt => dateTime().withDefault(currentTimestamp)();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};
diff --git a/mnemo_cards_backend/lib/database/tables/users.dart b/mnemo_cards_backend/lib/database/tables/users.dart
index 4947a12..16319f2 100644
--- a/mnemo_cards_backend/lib/database/tables/users.dart
+++ b/mnemo_cards_backend/lib/database/tables/users.dart
@@ -1,5 +1,6 @@
 import 'package:drift/drift.dart';
 import '../converters.dart';
+import '../postgres_constants.dart';
 
 /// Таблица Users - основная информация о пользователях
 class Users extends Table {
@@ -18,8 +19,8 @@ class Users extends Table {
       .map(const StringListConverter())();
   
   // Audit fields
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   BoolColumn get isDeleted => boolean().withDefault(const Constant(false))();
   
   @override
@@ -45,7 +46,7 @@ class UserDatas extends Table {
   
   // Временные метки
   DateTimeColumn get lastTimeOnline => dateTime().nullable()();
-  DateTimeColumn get registrationDate => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get registrationDate => dateTime().withDefault(currentTimestamp)();
   TextColumn get lastTestSessionToken => text().nullable()();
   
   // Сложные структуры (JSON)
@@ -74,8 +75,8 @@ class UserDatas extends Table {
       .map(const JsonMapConverter())();
   
   // Audit
-  DateTimeColumn get createdAt => dateTime().withDefault(currentDateAndTime)();
-  DateTimeColumn get updatedAt => dateTime().withDefault(currentDateAndTime)();
+  DateTimeColumn get createdAt => dateTime().withDefault(currentTimestamp)();
+  DateTimeColumn get updatedAt => dateTime().withDefault(currentTimestamp)();
   
   @override
   Set<Column> get primaryKey => {id};