diff --git a/internal/ingest/packet.go b/internal/ingest/packet.go
index 10222ba..fda5497 100644
--- a/internal/ingest/packet.go
+++ b/internal/ingest/packet.go
@@ -730,11 +730,7 @@ func (w *Worker) handlePacket(ctx context.Context, iata, pubkeyHex string, raw [
 		w.log.Error(fmt.Sprintf("db: upsert packet failed from %s/%s", iata, pubkeyHex), "error", err)
 		return
 	}
-	// Prefer an explicit RFC3339 offset; legacy timezone-less observers use UTC.
-	heardAt, err := time.Parse(time.RFC3339Nano, envelope.Timestamp)
-	if err != nil {
-		heardAt, err = time.Parse("2006-01-02T15:04:05", envelope.Timestamp)
-	}
+	heardAt, err := parseHeardAt(envelope.Timestamp)
 	if err != nil {
 		w.log.Warn(fmt.Sprintf("failed to parse timestamp %q", envelope.Timestamp), "error", err)
 		heardAt = time.Now().UTC()
@@ -959,3 +955,25 @@ func computeTransportCode(key []byte, payloadType uint8, payload []byte) uint16
 	}
 	return code
 }
+
+// heardAtLayouts lists offset forms first; timezone-less observers are read as UTC.
+// Fractional seconds are optional in every layout.
+var heardAtLayouts = []string{
+	time.RFC3339Nano,
+	"2006-01-02 15:04:05.999999999Z07:00",
+	"2006-01-02T15:04:05.999999999Z0700",
+	"2006-01-02 15:04:05.999999999Z0700",
+	"2006-01-02T15:04:05",
+	"2006-01-02 15:04:05",
+}
+
+func parseHeardAt(s string) (time.Time, error) {
+	var err error
+	for _, layout := range heardAtLayouts {
+		var t time.Time
+		if t, err = time.Parse(layout, s); err == nil {
+			return t, nil
+		}
+	}
+	return time.Time{}, err
+}
diff --git a/internal/ingest/timestamp_test.go b/internal/ingest/timestamp_test.go
index 1b5daf6..2010f63 100644
--- a/internal/ingest/timestamp_test.go
+++ b/internal/ingest/timestamp_test.go
@@ -49,16 +49,36 @@ func TestPacketTimestampFormatsAndSkew(t *testing.T) {
 	}
 	for _, precision := range []time.Duration{time.Second, time.Microsecond, time.Nanosecond} {
 		expected := want.Truncate(precision)
-		stamp := expected.Format("2006-01-02T15:04:05.999999999")
-		if got := capture(t, stamp); !got.Equal(expected) {
-			t.Fatalf("timezone-less UTC changed: got %s want %s", got, expected)
+		for _, layout := range []string{"2006-01-02T15:04:05.999999999", "2006-01-02 15:04:05.999999999"} {
+			stamp := expected.Format(layout)
+			t.Run("naive "+stamp, func(t *testing.T) {
+				if got := capture(t, stamp); !got.Equal(expected) {
+					t.Fatalf("timezone-less UTC changed: got %s want %s", got, expected)
+				}
+			})
 		}
 	}
+	west := time.FixedZone("west", -4*60*60)
+	for _, layout := range []string{
+		"2006-01-02 15:04:05.999999-07:00", // Python str(datetime)
+		"2006-01-02T15:04:05.999-0700",
+		"2006-01-02 15:04:05-0700",
+	} {
+		stamp := want.Truncate(time.Microsecond).In(west).Format(layout)
+		expected, _ := time.Parse(layout, stamp)
+		t.Run(stamp, func(t *testing.T) {
+			if got := capture(t, stamp); !got.Equal(expected) {
+				t.Fatalf("reported time changed: got %s want %s", got, expected)
+			}
+		})
+	}
 	for _, stamp := range []string{"", "invalid", "2026-09-29T25:00:00+00:00", time.Now().Add(31 * time.Minute).Format(time.RFC3339), time.Now().Add(-31 * time.Minute).Format(time.RFC3339)} {
-		before := time.Now().UTC()
-		got := capture(t, stamp)
-		if got.Before(before) || got.After(time.Now().UTC()) {
-			t.Fatalf("invalid/skewed time escaped server-time guard: %s => %s", stamp, got)
-		}
+		t.Run("guard "+stamp, func(t *testing.T) {
+			before := time.Now().UTC()
+			got := capture(t, stamp)
+			if got.Before(before) || got.After(time.Now().UTC()) {
+				t.Fatalf("invalid/skewed time escaped server-time guard: %s => %s", stamp, got)
+			}
+		})
 	}
 }