diff --git a/telemetry/aggregator.go b/telemetry/aggregator.go
index 875aaf4..1298ca2 100644
--- a/telemetry/aggregator.go
+++ b/telemetry/aggregator.go
@@ -40,7 +40,7 @@ func (a *Aggregator) Run(d time.Duration) {
 	// Ensure the specific key uids received a message after the end of the duration
 	// That way we know that this specific key uid has been connected
 	for receiverKeyUID := range receiverKeyUIDs {
-		ok, err := didReceivedMessageAfter(a.DB, receiverKeyUID, endsAt)
+		ok, err := didReceivedMessageBeforeAndAfter(a.DB, receiverKeyUID, startsAt, endsAt)
 		if err != nil {
 			log.Fatalf("could not check key UID: %s, because of %s", receiverKeyUID, err)
 		}
diff --git a/telemetry/aggregator_test.go b/telemetry/aggregator_test.go
index 245f233..2107721 100644
--- a/telemetry/aggregator_test.go
+++ b/telemetry/aggregator_test.go
@@ -40,6 +40,11 @@ func dropTables(db *sql.DB) {
 	db.Close()
 }
 
+func updateCreatedAt(db *sql.DB, m *ReceivedMessage) error {
+	_, err := db.Exec("UPDATE receivedMessages SET createdAt = $1 WHERE id = $2", m.CreatedAt, m.ID)
+	return err
+}
+
 func queryAggregatedMessage(db *sql.DB) ([]*ReceivedMessageAggregated, error) {
 	rows, err := db.Query("SELECT * FROM receivedMessageAggregated")
 	if err != nil {
@@ -90,6 +95,20 @@ func TestRunAggregatorSimple(t *testing.T) {
 	err = m.put(db)
 	require.NoError(t, err)
 
+	twoHourAndHalf := 5*time.Hour + time.Minute*30
+	m = &ReceivedMessage{
+		ChatID:         "3",
+		MessageHash:    "3",
+		ReceiverKeyUID: "1",
+		SentAt:         time.Now().Add(-twoHourAndHalf).Unix(),
+		Topic:          "1",
+	}
+	err = m.put(db)
+	require.NoError(t, err)
+	m.CreatedAt = m.SentAt
+	err = updateCreatedAt(db, m)
+	require.NoError(t, err)
+
 	agg := NewAggregator(db)
 
 	agg.Run(time.Hour)
@@ -138,6 +157,20 @@ func TestRunAggregatorSimpleWithMessageMissing(t *testing.T) {
 	err = m.put(db)
 	require.NoError(t, err)
 
+	twoHourAndHalf := 5*time.Hour + time.Minute*30
+	m = &ReceivedMessage{
+		ChatID:         "3",
+		MessageHash:    "4",
+		ReceiverKeyUID: "1",
+		SentAt:         time.Now().Add(-twoHourAndHalf).Unix(),
+		Topic:          "1",
+	}
+	err = m.put(db)
+	require.NoError(t, err)
+	m.CreatedAt = m.SentAt
+	err = updateCreatedAt(db, m)
+	require.NoError(t, err)
+
 	m = &ReceivedMessage{
 		ChatID:         "1",
 		MessageHash:    "1",
@@ -158,6 +191,19 @@ func TestRunAggregatorSimpleWithMessageMissing(t *testing.T) {
 	err = m.put(db)
 	require.NoError(t, err)
 
+	m = &ReceivedMessage{
+		ChatID:         "3",
+		MessageHash:    "4",
+		ReceiverKeyUID: "2",
+		SentAt:         time.Now().Add(-twoHourAndHalf).Unix(),
+		Topic:          "1",
+	}
+	err = m.put(db)
+	require.NoError(t, err)
+	m.CreatedAt = m.SentAt
+	err = updateCreatedAt(db, m)
+	require.NoError(t, err)
+
 	agg := NewAggregator(db)
 
 	agg.Run(time.Hour)
diff --git a/telemetry/receivedmessage.go b/telemetry/receivedmessage.go
index 874e769..4de8d47 100644
--- a/telemetry/receivedmessage.go
+++ b/telemetry/receivedmessage.go
@@ -55,13 +55,20 @@ func queryReceivedMessagesBetween(db *sql.DB, startsAt time.Time, endsAt time.Ti
 	return receivedMessages, nil
 }
 
-func didReceivedMessageAfter(db *sql.DB, receiverPublicKey string, after time.Time) (bool, error) {
-	var count int
-	err := db.QueryRow("SELECT COUNT(*) FROM receivedMessages WHERE receiverKeyUID = $1 AND createdAt > $2", receiverPublicKey, after.Unix()).Scan(&count)
+func didReceivedMessageBeforeAndAfter(db *sql.DB, receiverPublicKey string, before, after time.Time) (bool, error) {
+	var afterCount int
+	err := db.QueryRow("SELECT COUNT(*) FROM receivedMessages WHERE receiverKeyUID = $1 AND createdAt > $2", receiverPublicKey, after.Unix()).Scan(&afterCount)
 	if err != nil {
 		return false, err
 	}
-	return count > 0, nil
+
+	var beforeCount int
+	err = db.QueryRow("SELECT COUNT(*) FROM receivedMessages WHERE receiverKeyUID = $1 AND createdAt < $2", receiverPublicKey, before.Unix()).Scan(&beforeCount)
+	if err != nil {
+		return false, err
+	}
+
+	return afterCount > 0 && beforeCount > 0, nil
 }
 
 func (r *ReceivedMessage) put(db *sql.DB) error {