diff --git a/internal/service/platformevents/builder.go b/internal/service/platformevents/builder.go
index 97734bd..1fc269e 100644
--- a/internal/service/platformevents/builder.go
+++ b/internal/service/platformevents/builder.go
@@ -34,7 +34,7 @@ func BuildInboundEvents(msg *message.UnifiedMessage, result *dialog.Result, meta
 	}
 	eventIndex := 0
 	baseEvent := func(eventType string, payload map[string]any) platformevent.Event {
-		eventTime := now.Add(time.Duration(eventIndex) * time.Millisecond)
+		eventTime := now.Add(time.Duration(eventIndex) * time.Nanosecond)
 		eventIndex++
 		return platformevent.Event{
 			ID:              uuid.New().String(),
@@ -47,7 +47,7 @@ func BuildInboundEvents(msg *message.UnifiedMessage, result *dialog.Result, meta
 			Payload:         payload,
 			Status:          platformevent.StatusPending,
 			AttemptCount:    0,
-			NextAttemptAt:   now,
+			NextAttemptAt:   eventTime,
 			OccurredAt:      eventTime,
 			CreatedAt:       eventTime,
 			UpdatedAt:       eventTime,
diff --git a/internal/store/postgres/platform_event_store.go b/internal/store/postgres/platform_event_store.go
index 8081b0c..4f6e8ca 100644
--- a/internal/store/postgres/platform_event_store.go
+++ b/internal/store/postgres/platform_event_store.go
@@ -81,7 +81,7 @@ func (s *PlatformEventStore) ListDue(ctx context.Context, platform string, dueBe
 		       delivered_at, COALESCE(last_error, '')
 		FROM cs_platform_event_outbox
 		WHERE platform = $1 AND status IN ('pending', 'retrying') AND next_attempt_at <= $2
-		ORDER BY next_attempt_at ASC, created_at ASC
+		ORDER BY next_attempt_at ASC, occurred_at ASC, created_at ASC, id ASC
 		LIMIT $3
 	`, platform, dueBefore, limit)
 	if err != nil {
diff --git a/internal/store/postgres/platform_event_store_test.go b/internal/store/postgres/platform_event_store_test.go
index 828dede..bf5aab4 100644
--- a/internal/store/postgres/platform_event_store_test.go
+++ b/internal/store/postgres/platform_event_store_test.go
@@ -59,33 +59,31 @@ func TestPlatformEventStore_ShouldListPendingEventsInOrder(t *testing.T) {
 
 	store := NewPlatformEventStore(db)
 	now := time.Now().UTC().Truncate(time.Second)
-	firstID := uniqueID("evt")
-	secondID := uniqueID("evt")
-	platformName := "s2a-" + firstID[:8]
+	platformName := "s2a-" + uniqueID("plt")[:8]
 
 	first := &platformevent.Event{
-		ID:             firstID,
+		ID:             uniqueID("evt"),
 		Platform:       platformName,
-		EventType:      platformevent.TypeMessageProcessing,
+		EventType:      platformevent.TypeMessageReceived,
 		CallbackTarget: "default",
 		Payload:        map[string]any{"step": 1},
 		Status:         platformevent.StatusPending,
-		NextAttemptAt:  now.Add(-2 * time.Minute),
-		OccurredAt:     now.Add(-2 * time.Minute),
-		CreatedAt:      now.Add(-2 * time.Minute),
-		UpdatedAt:      now.Add(-2 * time.Minute),
+		NextAttemptAt:  now,
+		OccurredAt:     now.Add(-5 * time.Nanosecond),
+		CreatedAt:      now.Add(-5 * time.Nanosecond),
+		UpdatedAt:      now.Add(-5 * time.Nanosecond),
 	}
 	second := &platformevent.Event{
-		ID:             secondID,
+		ID:             uniqueID("evt"),
 		Platform:       platformName,
-		EventType:      platformevent.TypeReplyGenerated,
+		EventType:      platformevent.TypeMessageProcessing,
 		CallbackTarget: "default",
 		Payload:        map[string]any{"step": 2},
 		Status:         platformevent.StatusPending,
-		NextAttemptAt:  now.Add(-1 * time.Minute),
-		OccurredAt:     now.Add(-1 * time.Minute),
-		CreatedAt:      now.Add(-1 * time.Minute),
-		UpdatedAt:      now.Add(-1 * time.Minute),
+		NextAttemptAt:  now,
+		OccurredAt:     now.Add(-4 * time.Nanosecond),
+		CreatedAt:      now.Add(-4 * time.Nanosecond),
+		UpdatedAt:      now.Add(-4 * time.Nanosecond),
 	}
 
 	if err := store.InsertPending(context.Background(), second); err != nil {
@@ -103,21 +101,14 @@ func TestPlatformEventStore_ShouldListPendingEventsInOrder(t *testing.T) {
 		t.Fatalf("due events count = %d, want at least 2", len(events))
 	}
 
-	firstPos := -1
-	secondPos := -1
-	for i, event := range events {
-		if event.ID == firstID {
-			firstPos = i
-		}
-		if event.ID == secondID {
-			secondPos = i
-		}
+	if events[0].EventType != platformevent.TypeMessageReceived {
+		t.Fatalf("first due event type = %s, want %s", events[0].EventType, platformevent.TypeMessageReceived)
 	}
-	if firstPos == -1 || secondPos == -1 {
-		t.Fatalf("did not find inserted events in due list: first=%d second=%d", firstPos, secondPos)
+	if events[1].EventType != platformevent.TypeMessageProcessing {
+		t.Fatalf("second due event type = %s, want %s", events[1].EventType, platformevent.TypeMessageProcessing)
 	}
-	if firstPos >= secondPos {
-		t.Fatalf("event order invalid: firstPos=%d secondPos=%d", firstPos, secondPos)
+	if events[0].OccurredAt.After(events[1].OccurredAt) {
+		t.Fatalf("due events out of order: first occurred_at=%s second occurred_at=%s", events[0].OccurredAt, events[1].OccurredAt)
 	}
 }