diff --git a/backend/src/main/java/com/petshop/backend/service/AdoptionService.java b/backend/src/main/java/com/petshop/backend/service/AdoptionService.java
index 0e3c7a95..9855a3e6 100644
--- a/backend/src/main/java/com/petshop/backend/service/AdoptionService.java
+++ b/backend/src/main/java/com/petshop/backend/service/AdoptionService.java
@@ -81,6 +81,9 @@ public class AdoptionService {
                 : null;
         String adoptionStatus = normalizeAdoptionStatus(request.getAdoptionStatus());
         validatePetAvailability(pet, null, null);
+        if (ADOPTION_STATUS_COMPLETED.equalsIgnoreCase(adoptionStatus) && request.getAdoptionDate() != null && request.getAdoptionDate().isAfter(LocalDate.now())) {
+            throw new IllegalArgumentException("Cannot mark a future-dated adoption as Completed");
+        }
 
         Adoption adoption = new Adoption();
         adoption.setPet(pet);
@@ -91,7 +94,7 @@ public class AdoptionService {
         adoption.setAdoptionStatus(adoptionStatus);
 
         adoption = adoptionRepository.save(adoption);
-        syncPetStatus(pet, adoptionStatus, adoption.getAdoptionId());
+        syncPetStatus(pet, adoptionStatus, adoption.getAdoptionId(), customer);
         return mapToResponse(adoption);
     }
 
@@ -113,6 +116,9 @@ public class AdoptionService {
         String adoptionStatus = normalizeAdoptionStatus(request.getAdoptionStatus());
         Long currentPetId = adoption.getPet() != null ? adoption.getPet().getPetId() : null;
         validatePetAvailability(pet, adoption.getAdoptionId(), currentPetId);
+        if (ADOPTION_STATUS_COMPLETED.equalsIgnoreCase(adoptionStatus) && request.getAdoptionDate() != null && request.getAdoptionDate().isAfter(LocalDate.now())) {
+            throw new IllegalArgumentException("Cannot mark a future-dated adoption as Completed");
+        }
 
         adoption.setPet(pet);
         adoption.setCustomer(customer);
@@ -122,7 +128,7 @@ public class AdoptionService {
         adoption.setAdoptionStatus(adoptionStatus);
 
         adoption = adoptionRepository.save(adoption);
-        syncPetStatus(pet, adoptionStatus, adoption.getAdoptionId());
+        syncPetStatus(pet, adoptionStatus, adoption.getAdoptionId(), customer);
         return mapToResponse(adoption);
     }
 
@@ -216,13 +222,16 @@ public class AdoptionService {
         }
     }
 
-    private void syncPetStatus(Pet pet, String adoptionStatus, Long adoptionId) {
+    private void syncPetStatus(Pet pet, String adoptionStatus, Long adoptionId, User customer) {
         boolean completedElsewhere = adoptionId != null
                 && adoptionRepository.existsByPet_IdAndAdoptionStatusIgnoreCaseAndAdoptionIdNot(pet.getPetId(), ADOPTION_STATUS_COMPLETED, adoptionId);
         if (ADOPTION_STATUS_COMPLETED.equalsIgnoreCase(adoptionStatus) || completedElsewhere) {
             pet.setPetStatus(PET_STATUS_ADOPTED);
+            pet.setOwner(customer);
+            pet.setStore(null);
         } else {
             pet.setPetStatus(PET_STATUS_AVAILABLE);
+            pet.setOwner(null);
         }
         petRepository.save(pet);
     }
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AppointmentDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AppointmentDialogController.java
index 139255c6..495813ac 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AppointmentDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/AppointmentDialogController.java
@@ -18,6 +18,7 @@ import org.example.petshopdesktop.api.endpoints.DropdownApi;
 import org.example.petshopdesktop.auth.UserSession;
 import org.example.petshopdesktop.util.ActivityLogger;
 
+import java.time.DayOfWeek;
 import java.time.LocalTime;
 import java.time.LocalDate;
 import java.util.List;
@@ -65,7 +66,15 @@ public class AppointmentDialogController {
         cbPet.setPromptText("Select a customer first");
         cbCustomer.setPromptText("Select a customer");
         cbService.setPromptText("Select a service");
-        dpAppointmentDate.setValue(LocalDate.now().plusDays(1));
+        LocalDate minDate = minAppointmentDate();
+        dpAppointmentDate.setValue(minDate);
+        dpAppointmentDate.setDayCellFactory(picker -> new javafx.scene.control.DateCell() {
+            @Override
+            public void updateItem(LocalDate item, boolean empty) {
+                super.updateItem(item, empty);
+                setDisable(empty || item.isBefore(minDate));
+            }
+        });
         cbAppointmentStatus.setValue("Booked");
 
         for (int i = 9; i <= 17; i++) {
@@ -315,9 +324,20 @@ public class AppointmentDialogController {
             try {
                 List<DropdownOption> pets = DropdownApi.getInstance().getCustomerPets(customerId);
                 Platform.runLater(() -> {
-                    cbPet.setItems(FXCollections.observableArrayList(pets));
-                    cbPet.setDisable(pets == null || pets.isEmpty());
-                    cbPet.setPromptText(pets == null || pets.isEmpty() ? "No pets for selected customer" : "Select a pet");
+                    ObservableList<DropdownOption> petOptions = FXCollections.observableArrayList(pets != null ? pets : List.of());
+                    if (pendingPetSelectionId != null) {
+                        boolean found = petOptions.stream().anyMatch(p -> pendingPetSelectionId.equals(p.getId()));
+                        if (!found && selectedAppointment != null && selectedAppointment.getPetId() > 0) {
+                            DropdownOption placeholder = new DropdownOption();
+                            placeholder.setId((long) selectedAppointment.getPetId());
+                            placeholder.setLabel(selectedAppointment.getPetName() != null && !selectedAppointment.getPetName().isBlank()
+                                    ? selectedAppointment.getPetName() : "Pet #" + selectedAppointment.getPetId());
+                            petOptions.add(0, placeholder);
+                        }
+                    }
+                    cbPet.setItems(petOptions);
+                    cbPet.setDisable(petOptions.isEmpty());
+                    cbPet.setPromptText(petOptions.isEmpty() ? "No pets for selected customer" : "Select a pet");
                     if (pendingPetSelectionId != null) {
                         for (DropdownOption pet : cbPet.getItems()) {
                             if (pet.getId() != null && pet.getId().equals(pendingPetSelectionId)) {
@@ -392,6 +412,19 @@ public class AppointmentDialogController {
         }).start();
     }
 
+    private LocalDate minAppointmentDate() {
+        LocalDate date = LocalDate.now();
+        int businessDaysAdded = 0;
+        while (businessDaysAdded < 2) {
+            date = date.plusDays(1);
+            DayOfWeek dow = date.getDayOfWeek();
+            if (dow != DayOfWeek.SATURDAY && dow != DayOfWeek.SUNDAY) {
+                businessDaysAdded++;
+            }
+        }
+        return date;
+    }
+
     private void loadEmployees() {
         new Thread(() -> {
             try {
diff --git a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PetDialogController.java b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PetDialogController.java
index 5e4835e2..c6794758 100644
--- a/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PetDialogController.java
+++ b/desktop/src/main/java/org/example/petshopdesktop/controllers/dialogcontrollers/PetDialogController.java
@@ -247,7 +247,7 @@ public class PetDialogController {
         request.setPetAge(age);
 
         String status = cbPetStatus.getValue();
-        if ("Owned".equalsIgnoreCase(status) && cbCustomer.getValue() != null) {
+        if (("Owned".equalsIgnoreCase(status) || "Adopted".equalsIgnoreCase(status)) && cbCustomer.getValue() != null) {
             request.setCustomerId(cbCustomer.getValue().getId());
         }
         if (requiresStore(status) && cbStore.getValue() != null) {
@@ -432,9 +432,9 @@ public class PetDialogController {
     }
 
     private void updateStatusFieldVisibility(String status) {
-        boolean owned = "Owned".equalsIgnoreCase(status);
+        boolean needsCustomer = "Owned".equalsIgnoreCase(status) || "Adopted".equalsIgnoreCase(status);
         boolean storeBased = requiresStore(status);
-        setFieldVisibility(vbCustomerField, owned);
+        setFieldVisibility(vbCustomerField, needsCustomer);
         setFieldVisibility(vbStoreField, storeBased);
     }