работает

PlumbingRepair/PlumbingRepair/FormStore.cs

@@ -45,7 +45,7 @@ namespace PlumbingRepair
                     Id = _id ?? 0,
                     StoreName = NameTextBox.Text,
                     StoreAdress = AdressTextBox.Text,
-                    OpeningDate = OpeningDatePicker.Value.Date,
+                    OpeningDate = DateTime.SpecifyKind(OpeningDatePicker.Value.Date, DateTimeKind.Utc),
                     WorkMaxCount = (int)VolumeNumericUpDown.Value,
                     StoreWorks = _listStores
 				};

PlumbingRepair/PlumbingRepair/Program.cs

@@ -24,7 +24,7 @@ namespace PlumbingRepair
             ApplicationConfiguration.Initialize();
             var services = new ServiceCollection();
             ConfigureServices(services);
-            _serviceProvider = services.BuildServiceProvider();
+			_serviceProvider = services.BuildServiceProvider();
             Application.Run(_serviceProvider.GetRequiredService<FormMain>());
         }
         private static void ConfigureServices(ServiceCollection services)

PlumbingRepair/PlumbingRepairContracts/BindingModels/StoreBindingModel.cs

@@ -7,7 +7,7 @@ namespace PlumbingRepairContracts.BindingModels
         public string StoreName { get; set; } = string.Empty;
         public string StoreAdress { get; set; } = string.Empty;
 
-        public DateTime OpeningDate { get; set; } = DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Utc);
+        public DateTime OpeningDate { get; set; }
 
         public Dictionary<int, (IWorkModel, int)> StoreWorks { get; set; } = new();
 

PlumbingRepair/PlumbingRepairContracts/ViewModels/StoreViewModel.cs

@@ -13,7 +13,7 @@ namespace PlumbingRepairContracts.ViewModels
         [DisplayName("Адрес магазина")]
         public string StoreAdress { get; set; } = string.Empty;
         [DisplayName("Дата открытия")]
-        public DateTime OpeningDate { get; set; } = DateTime.Now;
+        public DateTime OpeningDate { get; set; }
         [DisplayName("Вместимость магазина")]
         public int WorkMaxCount { get; set; }
     }