feat: Implement UTC conversion for order date and time serialization in order use cases

apps/mobile/packages/core/lib/src/utils/time_utils.dart

@@ -68,3 +68,45 @@ String formatTime(String timeStr) {
     }
   }
 }
+
+/// Converts a local date + local HH:MM time string to a UTC HH:MM string.
+///
+/// Combines [localDate] with the hours and minutes from [localTime] (e.g.
+/// "09:00") to create a full local [DateTime], converts it to UTC, then
+/// extracts the HH:MM portion.
+///
+/// Example: March 19, "21:00" in UTC-5 → "02:00" (next day UTC).
+String toUtcTimeHHmm(DateTime localDate, String localTime) {
+  final List<String> parts = localTime.split(':');
+  final DateTime localDt = DateTime(
+    localDate.year,
+    localDate.month,
+    localDate.day,
+    int.parse(parts[0]),
+    int.parse(parts[1]),
+  );
+  final DateTime utcDt = localDt.toUtc();
+  return '${utcDt.hour.toString().padLeft(2, '0')}:'
+      '${utcDt.minute.toString().padLeft(2, '0')}';
+}
+
+/// Converts a local date + local HH:MM time string to a UTC YYYY-MM-DD string.
+///
+/// This accounts for date-boundary crossings: a shift at 11 PM on March 19
+/// in UTC-5 is actually March 20 in UTC.
+///
+/// Example: March 19, "23:00" in UTC-5 → "2026-03-20".
+String toUtcDateIso(DateTime localDate, String localTime) {
+  final List<String> parts = localTime.split(':');
+  final DateTime localDt = DateTime(
+    localDate.year,
+    localDate.month,
+    localDate.day,
+    int.parse(parts[0]),
+    int.parse(parts[1]),
+  );
+  final DateTime utcDt = localDt.toUtc();
+  return '${utcDt.year.toString().padLeft(4, '0')}-'
+      '${utcDt.month.toString().padLeft(2, '0')}-'
+      '${utcDt.day.toString().padLeft(2, '0')}';
+}

apps/mobile/packages/features/client/orders/create_order/lib/src/domain/arguments/one_time_order_arguments.dart

@@ -63,6 +63,39 @@ class OneTimeOrderArguments extends UseCaseArgument {
   /// The selected vendor ID, if applicable.
   final String? vendorId;
 
+  /// Serialises these arguments into the V2 API payload shape.
+  ///
+  /// Times and dates are converted to UTC so the backend's
+  /// `combineDateAndTime` helper receives the correct values.
+  Map<String, dynamic> toJson() {
+    final String firstStartTime =
+        positions.isNotEmpty ? positions.first.startTime : '00:00';
+    final String utcOrderDate = toUtcDateIso(orderDate, firstStartTime);
+
+    final List<Map<String, dynamic>> positionsList =
+        positions.map((OneTimeOrderPositionArgument p) {
+      return <String, dynamic>{
+        if (p.roleName != null) 'roleName': p.roleName,
+        if (p.roleId.isNotEmpty) 'roleId': p.roleId,
+        'workerCount': p.workerCount,
+        'startTime': toUtcTimeHHmm(orderDate, p.startTime),
+        'endTime': toUtcTimeHHmm(orderDate, p.endTime),
+        if (p.lunchBreak != null &&
+            p.lunchBreak != 'NO_BREAK' &&
+            p.lunchBreak!.isNotEmpty)
+          'lunchBreakMinutes': breakMinutesFromLabel(p.lunchBreak!),
+      };
+    }).toList();
+
+    return <String, dynamic>{
+      'hubId': hubId,
+      'eventName': eventName,
+      'orderDate': utcOrderDate,
+      'positions': positionsList,
+      if (vendorId != null) 'vendorId': vendorId,
+    };
+  }
+
   @override
   List<Object?> get props =>
       <Object?>[hubId, eventName, orderDate, positions, vendorId];

apps/mobile/packages/features/client/orders/create_order/lib/src/domain/arguments/permanent_order_arguments.dart

@@ -63,6 +63,51 @@ class PermanentOrderArguments extends UseCaseArgument {
   /// The selected vendor ID, if applicable.
   final String? vendorId;
 
+  /// Day-of-week labels in Sunday-first order, matching the V2 API convention.
+  static const List<String> _dayLabels = <String>[
+    'SUN',
+    'MON',
+    'TUE',
+    'WED',
+    'THU',
+    'FRI',
+    'SAT',
+  ];
+
+  /// Serialises these arguments into the V2 API payload shape.
+  ///
+  /// Times and dates are converted to UTC so the backend's
+  /// `combineDateAndTime` helper receives the correct values.
+  Map<String, dynamic> toJson() {
+    final String firstStartTime =
+        positions.isNotEmpty ? positions.first.startTime : '00:00';
+    final String utcStartDate = toUtcDateIso(startDate, firstStartTime);
+
+    final List<int> daysOfWeekList = daysOfWeek
+        .map((String day) => _dayLabels.indexOf(day) % 7)
+        .toList();
+
+    final List<Map<String, dynamic>> positionsList =
+        positions.map((PermanentOrderPositionArgument p) {
+      return <String, dynamic>{
+        if (p.roleName != null) 'roleName': p.roleName,
+        if (p.roleId.isNotEmpty) 'roleId': p.roleId,
+        'workerCount': p.workerCount,
+        'startTime': toUtcTimeHHmm(startDate, p.startTime),
+        'endTime': toUtcTimeHHmm(startDate, p.endTime),
+      };
+    }).toList();
+
+    return <String, dynamic>{
+      'hubId': hubId,
+      'eventName': eventName,
+      'startDate': utcStartDate,
+      'daysOfWeek': daysOfWeekList,
+      'positions': positionsList,
+      if (vendorId != null) 'vendorId': vendorId,
+    };
+  }
+
   @override
   List<Object?> get props => <Object?>[
         hubId,

apps/mobile/packages/features/client/orders/create_order/lib/src/domain/arguments/recurring_order_arguments.dart

@@ -67,6 +67,53 @@ class RecurringOrderArguments extends UseCaseArgument {
   /// The selected vendor ID, if applicable.
   final String? vendorId;
 
+  /// Day-of-week labels in Sunday-first order, matching the V2 API convention.
+  static const List<String> _dayLabels = <String>[
+    'SUN',
+    'MON',
+    'TUE',
+    'WED',
+    'THU',
+    'FRI',
+    'SAT',
+  ];
+
+  /// Serialises these arguments into the V2 API payload shape.
+  ///
+  /// Times and dates are converted to UTC so the backend's
+  /// `combineDateAndTime` helper receives the correct values.
+  Map<String, dynamic> toJson() {
+    final String firstStartTime =
+        positions.isNotEmpty ? positions.first.startTime : '00:00';
+    final String utcStartDate = toUtcDateIso(startDate, firstStartTime);
+    final String utcEndDate = toUtcDateIso(endDate, firstStartTime);
+
+    final List<int> recurrenceDaysList = recurringDays
+        .map((String day) => _dayLabels.indexOf(day) % 7)
+        .toList();
+
+    final List<Map<String, dynamic>> positionsList =
+        positions.map((RecurringOrderPositionArgument p) {
+      return <String, dynamic>{
+        if (p.roleName != null) 'roleName': p.roleName,
+        if (p.roleId.isNotEmpty) 'roleId': p.roleId,
+        'workerCount': p.workerCount,
+        'startTime': toUtcTimeHHmm(startDate, p.startTime),
+        'endTime': toUtcTimeHHmm(startDate, p.endTime),
+      };
+    }).toList();
+
+    return <String, dynamic>{
+      'hubId': hubId,
+      'eventName': eventName,
+      'startDate': utcStartDate,
+      'endDate': utcEndDate,
+      'recurrenceDays': recurrenceDaysList,
+      'positions': positionsList,
+      if (vendorId != null) 'vendorId': vendorId,
+    };
+  }
+
   @override
   List<Object?> get props => <Object?>[
         hubId,

apps/mobile/packages/features/client/orders/create_order/lib/src/domain/usecases/create_one_time_order_usecase.dart

@@ -1,49 +1,19 @@
-import 'package:krow_core/core.dart';
-
 import '../arguments/one_time_order_arguments.dart';
 import '../repositories/client_create_order_repository_interface.dart';
 
 /// Use case for creating a one-time staffing order.
 ///
-/// Builds the V2 API payload from typed [OneTimeOrderArguments] and
+/// Delegates payload construction to [OneTimeOrderArguments.toJson] and
-/// delegates submission to the repository. Payload construction (date
+/// submission to the repository.
-/// formatting, position mapping, break-minutes conversion) is business
+class CreateOneTimeOrderUseCase {
-/// logic that belongs here, not in the BLoC.
-class CreateOneTimeOrderUseCase
-    implements UseCase<OneTimeOrderArguments, void> {
   /// Creates a [CreateOneTimeOrderUseCase].
   const CreateOneTimeOrderUseCase(this._repository);
 
   /// The create-order repository.
   final ClientCreateOrderRepositoryInterface _repository;
 
-  @override
+  /// Creates a one-time order from the given arguments.
   Future<void> call(OneTimeOrderArguments input) {
-    final String orderDate = formatDateToIso(input.orderDate);
+    return _repository.createOneTimeOrder(input.toJson());
-
-    final List<Map<String, dynamic>> positions =
-        input.positions.map((OneTimeOrderPositionArgument p) {
-      return <String, dynamic>{
-        if (p.roleName != null) 'roleName': p.roleName,
-        if (p.roleId.isNotEmpty) 'roleId': p.roleId,
-        'workerCount': p.workerCount,
-        'startTime': p.startTime,
-        'endTime': p.endTime,
-        if (p.lunchBreak != null &&
-            p.lunchBreak != 'NO_BREAK' &&
-            p.lunchBreak!.isNotEmpty)
-          'lunchBreakMinutes': breakMinutesFromLabel(p.lunchBreak!),
-      };
-    }).toList();
-
-    final Map<String, dynamic> payload = <String, dynamic>{
-      'hubId': input.hubId,
-      'eventName': input.eventName,
-      'orderDate': orderDate,
-      'positions': positions,
-      if (input.vendorId != null) 'vendorId': input.vendorId,
-    };
-
-    return _repository.createOneTimeOrder(payload);
   }
 }

apps/mobile/packages/features/client/orders/create_order/lib/src/domain/usecases/create_permanent_order_usecase.dart

@@ -1,61 +1,19 @@
-import 'package:krow_core/core.dart';
-
 import '../arguments/permanent_order_arguments.dart';
 import '../repositories/client_create_order_repository_interface.dart';
 
-/// Day-of-week labels in Sunday-first order, matching the V2 API convention.
-const List<String> _dayLabels = <String>[
-  'SUN',
-  'MON',
-  'TUE',
-  'WED',
-  'THU',
-  'FRI',
-  'SAT',
-];
-
 /// Use case for creating a permanent staffing order.
 ///
-/// Builds the V2 API payload from typed [PermanentOrderArguments] and
+/// Delegates payload construction to [PermanentOrderArguments.toJson] and
-/// delegates submission to the repository. Payload construction (date
+/// submission to the repository.
-/// formatting, day-of-week mapping, position mapping) is business
+class CreatePermanentOrderUseCase {
-/// logic that belongs here, not in the BLoC.
-class CreatePermanentOrderUseCase
-    implements UseCase<PermanentOrderArguments, void> {
   /// Creates a [CreatePermanentOrderUseCase].
   const CreatePermanentOrderUseCase(this._repository);
 
   /// The create-order repository.
   final ClientCreateOrderRepositoryInterface _repository;
 
-  @override
+  /// Creates a permanent order from the given arguments.
   Future<void> call(PermanentOrderArguments input) {
-    final String startDate = formatDateToIso(input.startDate);
+    return _repository.createPermanentOrder(input.toJson());
-
-    final List<int> daysOfWeek = input.daysOfWeek
-        .map((String day) => _dayLabels.indexOf(day) % 7)
-        .toList();
-
-    final List<Map<String, dynamic>> positions =
-        input.positions.map((PermanentOrderPositionArgument p) {
-      return <String, dynamic>{
-        if (p.roleName != null) 'roleName': p.roleName,
-        if (p.roleId.isNotEmpty) 'roleId': p.roleId,
-        'workerCount': p.workerCount,
-        'startTime': p.startTime,
-        'endTime': p.endTime,
-      };
-    }).toList();
-
-    final Map<String, dynamic> payload = <String, dynamic>{
-      'hubId': input.hubId,
-      'eventName': input.eventName,
-      'startDate': startDate,
-      'daysOfWeek': daysOfWeek,
-      'positions': positions,
-      if (input.vendorId != null) 'vendorId': input.vendorId,
-    };
-
-    return _repository.createPermanentOrder(payload);
   }
 }

apps/mobile/packages/features/client/orders/create_order/lib/src/domain/usecases/create_recurring_order_usecase.dart

@@ -1,63 +1,19 @@
-import 'package:krow_core/core.dart';
-
 import '../arguments/recurring_order_arguments.dart';
 import '../repositories/client_create_order_repository_interface.dart';
 
-/// Day-of-week labels in Sunday-first order, matching the V2 API convention.
-const List<String> _dayLabels = <String>[
-  'SUN',
-  'MON',
-  'TUE',
-  'WED',
-  'THU',
-  'FRI',
-  'SAT',
-];
-
 /// Use case for creating a recurring staffing order.
 ///
-/// Builds the V2 API payload from typed [RecurringOrderArguments] and
+/// Delegates payload construction to [RecurringOrderArguments.toJson] and
-/// delegates submission to the repository. Payload construction (date
+/// submission to the repository.
-/// formatting, recurrence-day mapping, position mapping) is business
+class CreateRecurringOrderUseCase {
-/// logic that belongs here, not in the BLoC.
-class CreateRecurringOrderUseCase
-    implements UseCase<RecurringOrderArguments, void> {
   /// Creates a [CreateRecurringOrderUseCase].
   const CreateRecurringOrderUseCase(this._repository);
 
   /// The create-order repository.
   final ClientCreateOrderRepositoryInterface _repository;
 
-  @override
+  /// Creates a recurring order from the given arguments.
   Future<void> call(RecurringOrderArguments input) {
-    final String startDate = formatDateToIso(input.startDate);
+    return _repository.createRecurringOrder(input.toJson());
-    final String endDate = formatDateToIso(input.endDate);
-
-    final List<int> recurrenceDays = input.recurringDays
-        .map((String day) => _dayLabels.indexOf(day) % 7)
-        .toList();
-
-    final List<Map<String, dynamic>> positions =
-        input.positions.map((RecurringOrderPositionArgument p) {
-      return <String, dynamic>{
-        if (p.roleName != null) 'roleName': p.roleName,
-        if (p.roleId.isNotEmpty) 'roleId': p.roleId,
-        'workerCount': p.workerCount,
-        'startTime': p.startTime,
-        'endTime': p.endTime,
-      };
-    }).toList();
-
-    final Map<String, dynamic> payload = <String, dynamic>{
-      'hubId': input.hubId,
-      'eventName': input.eventName,
-      'startDate': startDate,
-      'endDate': endDate,
-      'recurrenceDays': recurrenceDays,
-      'positions': positions,
-      if (input.vendorId != null) 'vendorId': input.vendorId,
-    };
-
-    return _repository.createRecurringOrder(payload);
   }
 }

apps/mobile/packages/features/client/orders/view_orders/lib/src/data/repositories/view_orders_repository_impl.dart

@@ -22,8 +22,8 @@ class ViewOrdersRepositoryImpl implements ViewOrdersRepositoryInterface {
     final ApiResponse response = await _api.get(
       ClientEndpoints.ordersView,
       params: <String, dynamic>{
-        'startDate': start.toIso8601String(),
+        'startDate': start.toUtc().toIso8601String(),
-        'endDate': end.toIso8601String(),
+        'endDate': end.toUtc().toIso8601String(),
       },
     );
     final Map<String, dynamic> data = response.data as Map<String, dynamic>;

apps/mobile/packages/features/staff/shifts/lib/src/data/repositories_impl/shifts_repository_impl.dart

@@ -36,8 +36,8 @@ class ShiftsRepositoryImpl implements ShiftsRepositoryInterface {
     final ApiResponse response = await _apiService.get(
       StaffEndpoints.shiftsAssigned,
       params: <String, dynamic>{
-        'startDate': start.toIso8601String(),
+        'startDate': start.toUtc().toIso8601String(),
-        'endDate': end.toIso8601String(),
+        'endDate': end.toUtc().toIso8601String(),
       },
     );
     final List<dynamic> items = _extractItems(response.data);