diff --git a/backend/handlers/bookings/edit_requests_test.go b/backend/handlers/bookings/edit_requests_test.go
index f027f05..7296018 100644
--- a/backend/handlers/bookings/edit_requests_test.go
+++ b/backend/handlers/bookings/edit_requests_test.go
@@ -2387,3 +2387,93 @@ func TestAdminApproveEditRequest_ClosedExceptionalHours_Rejected(t *testing.T) {
 		t.Errorf("expected status 409 (conflict), got %d. body: %s", w.Code, w.Body.String())
 	}
 }
+
+// TestRequestEditHandler_PastClosing_Blocked verifies that proposing a time
+// whose end extends past closing hours returns a 400 error.
+// Uses the bookings test DB hours (all days 08:00-20:00).
+func TestRequestEditHandler_PastClosing_Blocked(t *testing.T) {
+	ctx, tx := testutils.SetupTestTx(t)
+	_, _, bookingID, token := setupEditRequestTest(t, ctx, tx)
+
+	// Test DB seed data: all days 08:00-20:00. Propose 19:30 which ends at
+	// 20:30 for a 60-min service — past the 20:00 closing.
+	nextDay := clock.Now().In(clock.London).AddDate(0, 0, 1)
+	pastClose := time.Date(nextDay.Year(), nextDay.Month(), nextDay.Day(), 19, 30, 0, 0, clock.London).UTC()
+
+	handler := http.HandlerFunc(RequestEditHandler)
+	w := makeRequest(handler, "POST", "/api/bookings/"+bookingID+"/edit-request", map[string]interface{}{
+		"new_start_time": pastClose.Format(time.RFC3339),
+	}, token, ctx)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected 400 for past-closing time, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+// TestRequestEditHandler_StagedHoursClosed_Blocked verifies that proposing a
+// time on a day that becomes closed under a staged default hours change is
+// blocked with a 400 error.
+func TestRequestEditHandler_StagedHoursClosed_Blocked(t *testing.T) {
+	ctx, tx := testutils.SetupTestTx(t)
+	_, serviceID, bookingID, token := setupEditRequestTest(t, ctx, tx)
+	_ = serviceID
+
+	// Insert a staged change closing a weekday that is normally open
+	adminID, err := fixtures.CreateTestAdminUser(tx)
+	if err != nil {
+		t.Fatalf("failed to create admin user: %v", err)
+	}
+	defer fixtures.DeleteUser(tx, adminID)
+
+	tomorrow := clock.Now().In(clock.London).AddDate(0, 0, 1).Format("2006-01-02")
+	// Stage: all days closed
+	hoursJSON := `[{"weekday":0,"startTime":"00:00","endTime":"00:00","isOpen":false},{"weekday":1,"startTime":"00:00","endTime":"00:00","isOpen":false},{"weekday":2,"startTime":"00:00","endTime":"00:00","isOpen":false},{"weekday":3,"startTime":"00:00","endTime":"00:00","isOpen":false},{"weekday":4,"startTime":"00:00","endTime":"00:00","isOpen":false},{"weekday":5,"startTime":"00:00","endTime":"00:00","isOpen":false},{"weekday":6,"startTime":"00:00","endTime":"00:00","isOpen":false}]`
+	_, err = tx.Exec(ctx, `
+		INSERT INTO default_hours_scheduled_changes (effective_date, created_by, hours)
+		VALUES ($1, $2, $3)
+	`, tomorrow, adminID, hoursJSON)
+	if err != nil {
+		t.Fatalf("failed to insert staged change: %v", err)
+	}
+
+	// Propose a time on a day that is now closed under the staged change
+	londonNow := clock.Now().In(clock.London)
+	target := londonNow.AddDate(0, 0, 1)
+	for target.Weekday() == time.Sunday {
+		target = target.AddDate(0, 0, 1)
+	}
+	proposedTime := time.Date(target.Year(), target.Month(), target.Day(), 10, 0, 0, 0, clock.London).UTC()
+
+	handler := http.HandlerFunc(RequestEditHandler)
+	w := makeRequest(handler, "POST", "/api/bookings/"+bookingID+"/edit-request", map[string]interface{}{
+		"new_start_time": proposedTime.Format(time.RFC3339),
+	}, token, ctx)
+
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected 400 for staged-closed day, got %d: %s", w.Code, w.Body.String())
+	}
+}
+
+// TestRequestEditHandler_ValidTime_Succeeds verifies that proposing a time
+// within open hours succeeds (returns 201).
+func TestRequestEditHandler_ValidTime_Succeeds(t *testing.T) {
+	ctx, tx := testutils.SetupTestTx(t)
+	_, _, bookingID, token := setupEditRequestTest(t, ctx, tx)
+
+	// Propose 10:00 on a weekday that is open
+	londonNow := clock.Now().In(clock.London)
+	target := londonNow.AddDate(0, 0, 1)
+	for target.Weekday() == time.Sunday {
+		target = target.AddDate(0, 0, 1)
+	}
+	validTime := time.Date(target.Year(), target.Month(), target.Day(), 10, 0, 0, 0, clock.London).UTC()
+
+	handler := http.HandlerFunc(RequestEditHandler)
+	w := makeRequest(handler, "POST", "/api/bookings/"+bookingID+"/edit-request", map[string]interface{}{
+		"new_start_time": validTime.Format(time.RFC3339),
+	}, token, ctx)
+
+	if w.Code != http.StatusCreated {
+		t.Errorf("expected 201 for valid time, got %d: %s", w.Code, w.Body.String())
+	}
+}