feat(bookings): add closing_time validation and repo layer

Extract closing hours check into reusable checkClosingHours helper. Add repo.go for shared DB query helpers. Update admin_reserve to use closing_time and move overlap check inside transaction with FOR UPDATE.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/handlers/bookings/admin_reserve.go

@@ -3,6 +3,7 @@ package bookings
 import (
 	"context"
 	"crussell/db"
+	"crussell/clock"
 	"github.com/jackc/pgx/v5"
 	"crussell/handlers/scheduling"
 	"crussell/mw"
@@ -78,7 +79,7 @@ func AdminReserveSlotHandler(w http.ResponseWriter, r *http.Request) {
 			http.Error(w, "At least one service or custom service is required for call-in bookings", http.StatusBadRequest)
 			return
 		}
-		if req.StartTime.Before(time.Now()) {
+		if req.StartTime.Before(clock.Now()) {
 			http.Error(w, "Start time cannot be in the past", http.StatusBadRequest)
 			return
 		}
@@ -100,7 +101,7 @@ func AdminReserveSlotHandler(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 		svcDuration = req.DurationMinutes
-		allowablePast := time.Now().Add(-1 * time.Minute)
+		allowablePast := clock.Now().Add(-1 * time.Minute)
 		if req.StartTime.Before(allowablePast) {
 			http.Error(w, "Start time cannot be more than 1 minute in the past", http.StatusBadRequest)
 			return
@@ -124,29 +125,17 @@ func AdminReserveSlotHandler(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 
-		localEnd := localStart.Add(time.Duration(svcDuration) * time.Minute)
-		closeTime, _ := time.Parse("15:04:05", closeStr)
-		if localEnd.Hour() > closeTime.Hour() || (localEnd.Hour() == closeTime.Hour() && localEnd.Minute() > closeTime.Minute()) {
+		localEndLondon := localStart.Add(time.Duration(svcDuration) * time.Minute).In(londonLocation)
+		if err := checkClosingHours(localEndLondon, closeStr); err != nil {
+			if errors.Is(err, ErrPastClosing) {
 				http.Error(w, "Cannot book this time - services would extend beyond closing hours", http.StatusBadRequest)
+			} else {
+				http.Error(w, "Invalid closing time in schedule", http.StatusInternalServerError)
+			}
 			return
 		}
 	}
 
-	var cnt int
-	if err := db.Conn.QueryRow(r.Context(), `
-		SELECT COUNT(*) FROM bookings WHERE status IN ('pending','confirmed','in_progress','completed')
-		AND start_time < $2
-		AND end_time > $1
-	`, req.StartTime, endTime).Scan(&cnt); err != nil {
-		log.Printf("Failed to check overlap: %v", err)
-		http.Error(w, "Internal server error", http.StatusInternalServerError)
-		return
-	}
-	if cnt > 0 {
-		http.Error(w, "Cannot book this time - slot overlaps with an existing booking", http.StatusConflict)
-		return
-	}
-
 	blockerOverlap, _, err := scheduling.CheckTimeBlockerOverlap(r.Context(), req.StartTime, endTime)
 	if err != nil {
 		log.Printf("Failed to check time blocker overlap: %v", err)
@@ -163,6 +152,35 @@ func AdminReserveSlotHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	defer tx.Rollback(r.Context())
 
+	// Check booking overlap inside transaction
+	// pending_release is excluded — those bookings are evicted at creation time
+	// by AdminCreateBookingForUserHandler / CreateBookingHandler.
+	overlapRows, err := tx.Query(r.Context(), `
+		SELECT 1 FROM bookings WHERE status IN ('pending','confirmed','in_progress','completed')
+		AND start_time < $2
+		AND end_time > $1
+		FOR UPDATE
+	`, req.StartTime, endTime)
+	if err != nil {
+		log.Printf("Failed to check overlap: %v", err)
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+	var cnt int
+	for overlapRows.Next() {
+		cnt++
+	}
+	overlapRows.Close()
+	if err := overlapRows.Err(); err != nil {
+		log.Printf("Overlap row iteration error: %v", err)
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+	if cnt > 0 {
+		http.Error(w, "Cannot book this time - slot overlaps with an existing booking", http.StatusConflict)
+		return
+	}
+
 	_, err = tx.Exec(r.Context(), `
 		DELETE FROM time_blockers
 		WHERE description LIKE 'RESERVATION:admin:%'
@@ -179,7 +197,7 @@ func AdminReserveSlotHandler(w http.ResponseWriter, r *http.Request) {
 		customerID = *req.UserID
 	}
 
-	description := fmt.Sprintf("RESERVATION:admin:%s:%s:%d", req.ReservationType, customerID, time.Now().UnixNano())
+	description := fmt.Sprintf("RESERVATION:admin:%s:%s:%d", req.ReservationType, customerID, clock.Now().UnixNano())
 	var reservationID string
 	var createdAt time.Time
 	err = tx.QueryRow(r.Context(), `
@@ -209,7 +227,7 @@ func AdminReserveSlotHandler(w http.ResponseWriter, r *http.Request) {
 		TTLMinutes:      req.TTLMinutes,
 	}
 
-	w.Header().Set("Content-Type", "application/json")
+
 	w.WriteHeader(http.StatusCreated)
 	if err := json.NewEncoder(w).Encode(response); err != nil {
 		log.Printf("Failed to encode response: %v", err)
@@ -246,7 +264,7 @@ func calculateServiceDurationWithOverrides(ctx context.Context, serviceIDs []str
 		SELECT id, duration_minutes FROM services WHERE id = ANY($1)
 		UNION ALL
 		SELECT id, duration_minutes FROM custom_services WHERE id = ANY($1)
-	`, serviceIDs, serviceIDs)
+	`, serviceIDs)
 	if err != nil {
 		return 0, err
 	}

backend/handlers/bookings/admin_reserve_test.go

@@ -19,6 +19,7 @@ import (
 	"testing"
 	"time"
 
+	"crussell/clock"
 	"crussell/testutils"
 	"crussell/mw"
 	"crussell/testutils/fixtures"
@@ -74,7 +75,7 @@ func TestAdminReserveSlot_WalkIn_Success(t *testing.T) {
 	}
 	defer fixtures.DeleteUser(tx, adminID)
 
-	tomorrow := time.Now().Add(24 * time.Hour)
+	tomorrow := clock.Now().Add(24 * time.Hour)
 	now := time.Date(tomorrow.Year(), tomorrow.Month(), tomorrow.Day(), 12, 0, 0, 0, tomorrow.Location())
 	req := AdminReserveSlotRequest{
 		ReservationType: "walkin",
@@ -149,7 +150,7 @@ func TestAdminReserveSlot_CallIn_Success(t *testing.T) {
 		t.Fatalf("failed to update service duration: %v", err)
 	}
 
-	tomorrow := time.Now().Add(24 * time.Hour).Truncate(time.Second)
+	tomorrow := clock.Now().Add(24 * time.Hour).Truncate(time.Second)
 	tomorrow = time.Date(tomorrow.Year(), tomorrow.Month(), tomorrow.Day(), 10, 0, 0, 0, tomorrow.Location())
 
 	req := AdminReserveSlotRequest{
@@ -209,7 +210,7 @@ func TestAdminReserveSlot_WalkIn_MissingDuration(t *testing.T) {
 	}
 	defer fixtures.DeleteUser(tx, adminID)
 
-	now := time.Now()
+	now := clock.Now()
 	req := AdminReserveSlotRequest{
 		ReservationType: "walkin",
 		StartTime:       now,
@@ -248,7 +249,7 @@ func TestAdminReserveSlot_CallIn_MissingServices(t *testing.T) {
 	}
 	defer fixtures.DeleteUser(tx, adminID)
 
-	tomorrow := time.Now().Add(24 * time.Hour).Truncate(time.Second)
+	tomorrow := clock.Now().Add(24 * time.Hour).Truncate(time.Second)
 	tomorrow = time.Date(tomorrow.Year(), tomorrow.Month(), tomorrow.Day(), 10, 0, 0, 0, tomorrow.Location())
 
 	req := AdminReserveSlotRequest{
@@ -292,7 +293,7 @@ func TestAdminReserveSlot_InvalidReservationType(t *testing.T) {
 
 	req := AdminReserveSlotRequest{
 		ReservationType: "invalid",
-		StartTime:       time.Now(),
+		StartTime:       clock.Now(),
 		DurationMinutes: 30,
 	}
 
@@ -348,7 +349,7 @@ func TestAdminReserveSlot_SlotOverlap(t *testing.T) {
 		t.Fatalf("failed to set deposits_required: %v", err)
 	}
 
-	tomorrow := time.Now().Add(24 * time.Hour).Truncate(time.Second)
+	tomorrow := clock.Now().Add(24 * time.Hour).Truncate(time.Second)
 	tomorrow = time.Date(tomorrow.Year(), tomorrow.Month(), tomorrow.Day(), 10, 0, 0, 0, tomorrow.Location())
 
 	bookingID, err := fixtures.CreateTestBooking(tx, userID, serviceID)
@@ -401,7 +402,7 @@ func TestAdminReserveSlot_ReplacesExisting(t *testing.T) {
 	}
 	defer fixtures.DeleteUser(tx, adminID)
 
-	tomorrow := time.Now().Add(24 * time.Hour)
+	tomorrow := clock.Now().Add(24 * time.Hour)
 	now := time.Date(tomorrow.Year(), tomorrow.Month(), tomorrow.Day(), 12, 0, 0, 0, tomorrow.Location())
 
 	req := AdminReserveSlotRequest{
@@ -490,7 +491,7 @@ func TestAdminReserveSlot_WalkIn_PastStart(t *testing.T) {
 	}
 	defer fixtures.DeleteUser(tx, adminID)
 
-	pastTime := time.Now().Add(-5 * time.Minute)
+	pastTime := clock.Now().Add(-5 * time.Minute)
 	req := AdminReserveSlotRequest{
 		ReservationType: "walkin",
 		StartTime:       pastTime,
@@ -533,7 +534,7 @@ func TestAdminReserveSlot_OutOfHours_CallIn_Success(t *testing.T) {
 
 	// Baseline test DB has 08:00-20:00 hours. Book 19:30 + 60min = 20:30 (> 20:00 closing)
 	// Without out_of_hours this would fail; with out_of_hours=true it should succeed.
-	tomorrow := time.Now().Add(24 * time.Hour)
+	tomorrow := clock.Now().Add(24 * time.Hour)
 	lateBooking := time.Date(tomorrow.Year(), tomorrow.Month(), tomorrow.Day(), 19, 30, 0, 0, tomorrow.Location())
 
 	req := AdminReserveSlotRequest{
@@ -582,7 +583,7 @@ func TestAdminReserveSlot_OutOfHours_WithoutFlag_Fails(t *testing.T) {
 
 	// Baseline test DB has 08:00-20:00 hours. Book 19:30 + 60min = 20:30 (> 20:00 closing)
 	// Without out_of_hours this should be rejected.
-	tomorrow := time.Now().Add(24 * time.Hour)
+	tomorrow := clock.Now().Add(24 * time.Hour)
 	lateBooking := time.Date(tomorrow.Year(), tomorrow.Month(), tomorrow.Day(), 19, 30, 0, 0, tomorrow.Location())
 
 	req := AdminReserveSlotRequest{
@@ -617,7 +618,7 @@ func TestAdminReserveSlot_OutOfHours_WalkIn_Success(t *testing.T) {
 
 	// Baseline test DB has 08:00-20:00 hours. Book walk-in 19:30 + 60min = 20:30 (> 20:00 closing)
 	// Without out_of_hours this would fail; with out_of_hours=true it should succeed.
-	tomorrow := time.Now().Add(24 * time.Hour)
+	tomorrow := clock.Now().Add(24 * time.Hour)
 	lateBooking := time.Date(tomorrow.Year(), tomorrow.Month(), tomorrow.Day(), 19, 30, 0, 0, tomorrow.Location())
 
 	req := AdminReserveSlotRequest{
@@ -672,7 +673,7 @@ func TestAdminReserveSlot_OutOfHours_TimeBlockerBlocks(t *testing.T) {
 	defer fixtures.DeleteUser(tx, adminID)
 
 	// Create a time blocker at a specific future time
-	tomorrow := time.Now().Add(24 * time.Hour)
+	tomorrow := clock.Now().Add(24 * time.Hour)
 	blockerStart := time.Date(tomorrow.Year(), tomorrow.Month(), tomorrow.Day(), 14, 0, 0, 0, tomorrow.Location())
 	_, err = tx.Exec(ctx, `
 		INSERT INTO time_blockers (start_time, duration_minutes, description, created_by)
@@ -700,5 +701,295 @@ func TestAdminReserveSlot_OutOfHours_TimeBlockerBlocks(t *testing.T) {
 	}
 }
 
+// TestAdminReserveSlot_BST_ClosingBoundary verifies that during BST (UTC+1),
+// the closing-time check uses London local time, not UTC. A booking ending at
+// 20:01 BST (19:01 UTC) should be rejected when closing is 20:00 BST, even
+// though the UTC hour (19) is before the closing hour (20). Seed data has
+// working hours 08:00-20:00 for all days.
+func TestAdminReserveSlot_BST_ClosingBoundary(t *testing.T) {
+	t.Parallel()
+	ctx, tx := testutils.SetupTestTx(t)
+
+	adminID, err := fixtures.CreateTestAdminUser(tx)
+	if err != nil {
+		t.Fatalf("failed to create admin: %v", err)
+	}
+	defer fixtures.DeleteUser(tx, adminID)
+
+	// Use a Monday in BST (2099-06-15 is a Monday in BST). Seed working hours
+	// for Monday are 08:00-20:00.
+	// Start at 18:31 UTC (= 19:31 BST), 30 min duration → ends at 19:01 UTC (= 20:01 BST).
+	// This should be rejected because 20:01 BST > 20:00 BST closing.
+	// Without .In(londonLocation), UTC hour 19 < closing 20, so this would
+	// incorrectly pass — the fix catches it.
+	bstDay := time.Date(2099, 6, 15, 18, 31, 0, 0, time.UTC)
+	req := AdminReserveSlotRequest{
+		ReservationType: "walkin",
+		StartTime:       bstDay,
+		DurationMinutes: 30,
+		TTLMinutes:      15,
+	}
+
+	handler := http.HandlerFunc(AdminReserveSlotHandler)
+	w := makeAdminReserveRequest(handler, req, adminID, ctx)
+
+	// Must be rejected (exceeds closing hours in London time).
+	// Without .In(londonLocation), UTC hour 19 would be < closing 20 and pass.
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("expected 400 BadRequest (exceeds closing hours in BST), got %d. body: %s", w.Code, w.Body.String())
+	}
+
+	// Verify the error message mentions closing hours.
+	if !strings.Contains(w.Body.String(), "closing hours") && !strings.Contains(w.Body.String(), "closing") {
+		t.Errorf("expected error about closing hours, got: %s", w.Body.String())
+	}
+
+	// Now test a booking that ends within closing hours (19:30 BST < 20:00 BST).
+	// Start at 18:00 UTC (= 19:00 BST), 30 min duration → ends at 18:30 UTC (= 19:30 BST).
+	bstDayOK := time.Date(2099, 6, 15, 18, 0, 0, 0, time.UTC)
+	req2 := AdminReserveSlotRequest{
+		ReservationType: "walkin",
+		StartTime:       bstDayOK,
+		DurationMinutes: 30,
+		TTLMinutes:      15,
+	}
+
+	w2 := makeAdminReserveRequest(handler, req2, adminID, ctx)
+	if w2.Code != http.StatusCreated {
+		t.Errorf("expected 201 Created (within closing hours in BST), got %d. body: %s", w2.Code, w2.Body.String())
+	}
+}
+
+// =============================================================================
+// Autumn DST (BST→GMT Transition) Tests
+// =============================================================================
+
+// TestAdminReserveSlot_AutumnDST_ClosingBoundary verifies that during autumn DST
+// (BST→GMT transition on Oct 25, 2026), the closing-time check works correctly
+// when London is in GMT (UTC+0). After the transition at 02:00 BST (→ 01:00 GMT),
+// local time equals UTC. This test sets Sunday's closing to 17:00 and verifies:
+//  1. A slot ending exactly at 17:00 GMT (= 17:00 UTC) is allowed (end == closing)
+//  2. A slot ending 1 minute after 17:00 GMT (= 17:01 UTC) is rejected
+//
+// Use of londonLocation for time.Date construction ensures the test time is
+// interpreted in the local timezone context of the autumn DST transition day.
+func TestAdminReserveSlot_AutumnDST_ClosingBoundary(t *testing.T) {
+	t.Parallel()
+	ctx, tx := testutils.SetupTestTx(t)
+
+	adminID, err := fixtures.CreateTestAdminUser(tx)
+	if err != nil {
+		t.Fatalf("failed to create admin: %v", err)
+	}
+	defer fixtures.DeleteUser(tx, adminID)
+
+	// Oct 25, 2026 is a Sunday (DB weekday 6). BST ends at 02:00 BST (→ 01:00 GMT),
+	// so the entire working day is in GMT. Override Sunday's closing to 17:00 to test
+	// the closing boundary on the autumn DST transition day.
+	_, err = tx.Exec(ctx, `
+		INSERT INTO working_hours (weekday, start_time, end_time, is_open)
+		VALUES (6, '08:00', '17:00', true)
+		ON CONFLICT (weekday) DO UPDATE SET start_time = '08:00', end_time = '17:00', is_open = true
+	`)
+	if err != nil {
+		t.Fatalf("failed to set Sunday working hours: %v", err)
+	}
+
+	handler := http.HandlerFunc(AdminReserveSlotHandler)
+
+	// Test 1: End exactly at 17:00 GMT (= 17:00 UTC, since GMT = UTC+0).
+	// Start 16:30 GMT + 30 min → ends 17:00 GMT → end == closing, allowed.
+	closingSlot := time.Date(2026, 10, 25, 16, 30, 0, 0, londonLocation)
+	req1 := AdminReserveSlotRequest{
+		ReservationType: "walkin",
+		StartTime:       closingSlot,
+		DurationMinutes: 30,
+		TTLMinutes:      15,
+	}
+	w1 := makeAdminReserveRequest(handler, req1, adminID, ctx)
+	if w1.Code != http.StatusCreated {
+		t.Errorf("ending exactly at 17:00 GMT: expected 201 (end == closing allowed), got %d. body: %s",
+			w1.Code, w1.Body.String())
+	}
+
+	// Parse response and verify duration
+	var resp1 AdminReserveSlotResponse
+	if err := json.Unmarshal(w1.Body.Bytes(), &resp1); err != nil {
+		t.Fatalf("failed to parse response: %v", err)
+	}
+	if resp1.DurationMinutes != 30 {
+		t.Errorf("expected duration 30, got %d", resp1.DurationMinutes)
+	}
+
+	// Test 2: End 1 min after 17:00 GMT (= 17:01 UTC).
+	// Start 16:31 GMT + 30 min → ends 17:01 GMT → rejected (past closing).
+	pastClose := time.Date(2026, 10, 25, 16, 31, 0, 0, londonLocation)
+	req2 := AdminReserveSlotRequest{
+		ReservationType: "walkin",
+		StartTime:       pastClose,
+		DurationMinutes: 30,
+		TTLMinutes:      15,
+	}
+	w2 := makeAdminReserveRequest(handler, req2, adminID, ctx)
+	if w2.Code != http.StatusBadRequest {
+		t.Errorf("ending 1 min after 17:00 GMT: expected 400, got %d. body: %s",
+			w2.Code, w2.Body.String())
+	}
+
+	// Verify error message mentions closing hours
+	if !strings.Contains(w2.Body.String(), "closing hours") && !strings.Contains(w2.Body.String(), "closing") {
+		t.Errorf("expected error about closing hours, got: %s", w2.Body.String())
+	}
+}
+
+// TestAdminReserveSlot_BST_WeekdayLookup verifies that the weekday used for
+// working-hours lookup uses London time, not UTC. At 23:30 UTC on a Sunday
+// in BST (= 00:30 BST Monday), UTC says Sunday (DB weekday 6) but London says
+// Monday (DB weekday 0). Deleting Sunday's row should cause failure WITHOUT
+// the fix, but succeed WITH the fix (London-time weekday=Monday, row exists).
+func TestAdminReserveSlot_BST_WeekdayLookup(t *testing.T) {
+	t.Parallel()
+	ctx, tx := testutils.SetupTestTx(t)
+
+	adminID, err := fixtures.CreateTestAdminUser(tx)
+	if err != nil {
+		t.Fatalf("failed to create admin: %v", err)
+	}
+	defer fixtures.DeleteUser(tx, adminID)
+
+	// Delete Sunday's (DB weekday 6) working hours row.
+	_, err = tx.Exec(ctx, "DELETE FROM working_hours WHERE weekday = 6")
+	if err != nil {
+		t.Fatalf("failed to delete Sunday hours: %v", err)
+	}
+
+	// Also seed Monday (weekday 0) explicitly so the test doesn't depend on fixture defaults.
+	_, err = tx.Exec(ctx, `
+	    INSERT INTO working_hours (weekday, start_time, end_time, is_open)
+	    VALUES (0, '09:00', '17:00', true)
+	    ON CONFLICT (weekday) DO UPDATE SET start_time = '09:00', end_time = '17:00', is_open = true
+	`)
+	if err != nil {
+		t.Fatalf("failed to seed Monday hours: %v", err)
+	}
+
+	// Book at 23:30 UTC on a Sunday in BST (2099-06-14 is Sunday, 2099-06-15 is Monday).
+	// 23:30 UTC Sunday = 00:30 BST Monday. London time = Monday (DB weekday 0, exists).
+	// UTC time = Sunday (DB weekday 6, deleted).
+	sunday2330UTC := time.Date(2099, 6, 14, 23, 30, 0, 0, time.UTC)
+	req := AdminReserveSlotRequest{
+		ReservationType: "walkin",
+		StartTime:       sunday2330UTC,
+		DurationMinutes: 30,
+		TTLMinutes:      15,
+	}
+
+	handler := http.HandlerFunc(AdminReserveSlotHandler)
+	w := makeAdminReserveRequest(handler, req, adminID, ctx)
+
+	if w.Code != http.StatusCreated {
+		t.Errorf("expected 201 Created (London weekday=Monday, row exists), got %d. body: %s — UTC weekday=Sunday (deleted), London weekday=Monday (exists)", w.Code, w.Body.String())
+	}
+}
+
+// TestAdminReserveSlot_ClosingComparison_EdgeCases verifies that the closing-time
+// string comparison correctly handles edge cases at the boundary (BUG 5 fix).
+// Tests: ending exactly at closing, 1 min before, and 1 min after.
+func TestAdminReserveSlot_ClosingComparison_EdgeCases(t *testing.T) {
+	t.Parallel()
+	ctx, tx := testutils.SetupTestTx(t)
+
+	adminID, err := fixtures.CreateTestAdminUser(tx)
+	if err != nil {
+		t.Fatalf("failed to create admin: %v", err)
+	}
+	defer fixtures.DeleteUser(tx, adminID)
+
+	// Seed data has all days open 08:00-20:00. Test various closing edges.
+	// Use a BST Monday (2099-06-15, BST period so UTC != London).
+	// 20:00 BST = 19:00 UTC. A service ending at 19:59 UTC = 20:59 BST (after closing).
+	// Actually seed data is 08:00-20:00 BST, so 20:00 BST closing = 19:00 UTC.
+
+	// Test 1: End exactly at closing (20:00 BST = 19:00 UTC) — should be allowed
+	// (end == closing is not "beyond" closing — the check is strict greater-than).
+	endAtClose := time.Date(2099, 6, 15, 18, 30, 0, 0, time.UTC) // start 18:30 UTC
+	req1 := AdminReserveSlotRequest{
+		ReservationType: "walkin",
+		StartTime:       endAtClose,
+		DurationMinutes: 30,
+		TTLMinutes:      15,
+	}
+	handler := http.HandlerFunc(AdminReserveSlotHandler)
+	w1 := makeAdminReserveRequest(handler, req1, adminID, ctx)
+	if w1.Code != http.StatusCreated {
+		t.Errorf("closing exactly at 20:00 BST: expected 201 (end == closing is allowed), got %d", w1.Code)
+	}
+
+	// Test 2: End 1 minute after closing (20:01 BST = 19:01 UTC) — should reject
+	oneMinAfter := time.Date(2099, 6, 15, 18, 31, 0, 0, time.UTC)
+	req2 := AdminReserveSlotRequest{
+		ReservationType: "walkin",
+		StartTime:       oneMinAfter,
+		DurationMinutes: 30,
+		TTLMinutes:      15,
+	}
+	w2 := makeAdminReserveRequest(handler, req2, adminID, ctx)
+	if w2.Code != http.StatusBadRequest {
+		t.Errorf("closing 1 min after 20:00 BST: expected 400, got %d", w2.Code)
+	}
+}
+
+// TestAdminReserveSlot_PendingRelease_DoesNotBlock verifies that a
+// pending_release booking does NOT block the admin reserve endpoint.
+// Like the user-facing reserve, admin reserves are pre-checks — eviction
+// happens when the actual booking is created.
+func TestAdminReserveSlot_PendingRelease_DoesNotBlock(t *testing.T) {
+	t.Parallel()
+	ctx, tx := testutils.SetupTestTx(t)
+
+	adminID, err := fixtures.CreateTestAdminUser(tx)
+	if err != nil {
+		t.Fatalf("failed to create admin: %v", err)
+	}
+
+	userID, err := fixtures.CreateTestUser(tx)
+	if err != nil {
+		t.Fatalf("failed to create test user: %v", err)
+	}
+
+	serviceID, err := fixtures.CreateTestService(tx)
+	if err != nil {
+		t.Fatalf("failed to create test service: %v", err)
+	}
+
+	future := clock.Now().Add(7 * 24 * time.Hour).Truncate(24 * time.Hour).Add(10 * time.Hour)
+
+	// Create a pending_release booking at this time slot
+	_, err = tx.Exec(ctx, `
+		INSERT INTO bookings (user_id, start_time, status, deposit_required)
+		VALUES ($1, $2, 'pending_release', false)
+	`, userID, future)
+	if err != nil {
+		t.Fatalf("failed to create pending_release booking: %v", err)
+	}
+
+	// Admin reserves the same slot — should succeed
+	req := AdminReserveSlotRequest{
+		ReservationType: "callin",
+		StartTime:       future,
+		ServiceIDs:      []string{serviceID},
+		TTLMinutes:      15,
+	}
+	handler := http.HandlerFunc(AdminReserveSlotHandler)
+	w := makeAdminReserveRequest(handler, req, adminID, ctx)
+
+	if w.Code == http.StatusConflict {
+		t.Errorf("pending_release should NOT block admin reserve – it is evictable, got 409")
+	}
+	if w.Code != http.StatusCreated {
+		t.Errorf("expected 201 for admin reserve with only pending_release overlap, got %d. body: %s", w.Code, w.Body.String())
+	}
+}
+
 // TestAdminReserveSlot_SlotOverlap tests that a reservation fails when the
 // requested time slot overlaps with an existing booking.

backend/handlers/bookings/closing_time.go

@@ -0,0 +1,35 @@
+package bookings
+
+import (
+	"errors"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// ErrPastClosing is returned by checkClosingHours when the booking's end time
+// exceeds the working hours closing time for that day.
+var ErrPastClosing = errors.New("booking extends beyond closing hours")
+
+// checkClosingHours verifies that a booking end time (in Europe/London wall-clock
+// time) does not exceed the closing time stored as "HH:MM" in the working_hours
+// table. Returns ErrPastClosing if the booking runs past close, or a generic
+// error if closeStr cannot be parsed.
+func checkClosingHours(localEnd time.Time, closeStr string) error {
+	parts := strings.Split(closeStr, ":")
+	if len(parts) < 2 {
+		return errors.New("invalid closing time format")
+	}
+	closeHour, err := strconv.Atoi(parts[0])
+	if err != nil {
+		return errors.New("invalid closing time format")
+	}
+	closeMin, err := strconv.Atoi(parts[1])
+	if err != nil {
+		return errors.New("invalid closing time format")
+	}
+	if localEnd.Hour() > closeHour || (localEnd.Hour() == closeHour && localEnd.Minute() > closeMin) {
+		return ErrPastClosing
+	}
+	return nil
+}

backend/handlers/bookings/closing_time_test.go

@@ -0,0 +1,94 @@
+//go:build test && dev
+// +build test,dev
+
+package bookings
+
+import (
+	"testing"
+	"time"
+)
+
+func TestCheckClosingHours_WithinHours(t *testing.T) {
+	// Closing at 17:00, booking ends at 16:30 — should pass.
+	london, err := time.LoadLocation("Europe/London")
+	if err != nil {
+		t.Fatalf("failed to load location: %v", err)
+	}
+	localEnd := time.Date(2026, 6, 24, 16, 30, 0, 0, london)
+	if err := checkClosingHours(localEnd, "17:00"); err != nil {
+		t.Errorf("expected no error for 16:30 end vs 17:00 close, got: %v", err)
+	}
+}
+
+func TestCheckClosingHours_AtClosing(t *testing.T) {
+	// Closing at 17:00, booking ends exactly at 17:00 — should pass.
+	london, err := time.LoadLocation("Europe/London")
+	if err != nil {
+		t.Fatalf("failed to load location: %v", err)
+	}
+	localEnd := time.Date(2026, 6, 24, 17, 0, 0, 0, london)
+	if err := checkClosingHours(localEnd, "17:00"); err != nil {
+		t.Errorf("expected no error for 17:00 end vs 17:00 close, got: %v", err)
+	}
+}
+
+func TestCheckClosingHours_PastClosing(t *testing.T) {
+	// Closing at 17:00, booking ends at 17:01 — should return ErrPastClosing.
+	london, err := time.LoadLocation("Europe/London")
+	if err != nil {
+		t.Fatalf("failed to load location: %v", err)
+	}
+	localEnd := time.Date(2026, 6, 24, 17, 1, 0, 0, london)
+	if err := checkClosingHours(localEnd, "17:00"); !IsPastClosing(err) {
+		t.Errorf("expected ErrPastClosing for 17:01 end vs 17:00 close, got: %v", err)
+	}
+}
+
+func TestCheckClosingHours_WellPastClosing(t *testing.T) {
+	// Closing at 17:00, booking ends at 18:00 — should return ErrPastClosing.
+	london, err := time.LoadLocation("Europe/London")
+	if err != nil {
+		t.Fatalf("failed to load location: %v", err)
+	}
+	localEnd := time.Date(2026, 6, 24, 18, 0, 0, 0, london)
+	if err := checkClosingHours(localEnd, "17:00"); !IsPastClosing(err) {
+		t.Errorf("expected ErrPastClosing for 18:00 end vs 17:00 close, got: %v", err)
+	}
+}
+
+func TestCheckClosingHours_InvalidFormat(t *testing.T) {
+	// Malformed closing time string — should return a generic error, not ErrPastClosing.
+	london, err := time.LoadLocation("Europe/London")
+	if err != nil {
+		t.Fatalf("failed to load location: %v", err)
+	}
+	localEnd := time.Date(2026, 6, 24, 14, 0, 0, 0, london)
+
+	tests := []struct {
+		name      string
+		closeStr  string
+	}{
+		{"empty string", ""},
+		{"no colon", "1700"},
+		{"non-numeric hour", "ab:00"},
+		{"non-numeric minute", "17:ab"},
+		{"only hour", "17"},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			err := checkClosingHours(localEnd, tc.closeStr)
+			if err == nil {
+				t.Error("expected error for invalid format, got nil")
+			}
+			if IsPastClosing(err) {
+				t.Errorf("expected non-past-closing error for invalid format %q, got ErrPastClosing", tc.closeStr)
+			}
+		})
+	}
+}
+
+// IsPastClosing reports whether err indicates the booking extends beyond closing hours.
+// Exported helper for tests.
+func IsPastClosing(err error) bool {
+	return err == ErrPastClosing
+}

backend/handlers/bookings/repo.go

@@ -0,0 +1,46 @@
+package bookings
+
+import (
+	"context"
+	"time"
+
+	"crussell/db"
+)
+
+// GetBookingStatus returns the status of a booking by ID.
+// Uses db.Conn directly — not for use inside transactions.
+func GetBookingStatus(ctx context.Context, bookingID string) (string, error) {
+	var status string
+	err := db.Conn.QueryRow(ctx, `SELECT status FROM bookings WHERE id = $1`, bookingID).Scan(&status)
+	if err != nil {
+		return "", err
+	}
+	return status, nil
+}
+
+// GetBookingStartTime returns the start_time of a booking by ID.
+// Uses db.Conn directly — not for use inside transactions.
+func GetBookingStartTime(ctx context.Context, bookingID string) (time.Time, error) {
+	var startTime time.Time
+	err := db.Conn.QueryRow(ctx, `SELECT start_time FROM bookings WHERE id = $1`, bookingID).Scan(&startTime)
+	if err != nil {
+		return time.Time{}, err
+	}
+	return startTime, nil
+}
+
+// BookingExists checks if a booking with the given ID exists.
+// Uses db.Conn directly — not for use inside transactions.
+func BookingExists(ctx context.Context, bookingID string) (bool, error) {
+	var exists bool
+	err := db.Conn.QueryRow(ctx, `SELECT EXISTS(SELECT 1 FROM bookings WHERE id = $1)`, bookingID).Scan(&exists)
+	return exists, err
+}
+
+// CountUserBookingsInStatus counts the number of bookings for a user with a specific status.
+// Uses db.Conn directly — not for use inside transactions.
+func CountUserBookingsInStatus(ctx context.Context, userID, status string) (int, error) {
+	var count int
+	err := db.Conn.QueryRow(ctx, `SELECT COUNT(*) FROM bookings WHERE user_id = $1 AND status = $2`, userID, status).Scan(&count)
+	return count, err
+}