diff --git a/src/rivian/parallax/dynamics.py b/src/rivian/parallax/dynamics.py
index 0420d32..5f374f4 100644
--- a/src/rivian/parallax/dynamics.py
+++ b/src/rivian/parallax/dynamics.py
@@ -93,16 +93,20 @@ def decode_gear(m: dynamics_pb2.Gear) -> dict[str, Any]:
     return {"gearStatus": _enum(_GEAR_MAP, m.gear, what="gear")}
 
 
-# Some vehicles send the fix time as GPS time (milliseconds since the GPS
-# epoch, 1980-01-06, without leap seconds) instead of Unix time. Any time
-# before 2020 is taken as GPS time.
+# Vehicles send the fix time in Unix milliseconds, Unix seconds, or GPS time
+# (milliseconds since the GPS epoch, 1980-01-06, without leap seconds). Any
+# time below 10^11 (1973 in ms, year 5138 in seconds) is taken as seconds, and
+# then any time before 2020 as GPS time.
 _GPS_EPOCH_OFFSET_MS: Final = 315_964_800_000
 _GPS_LEAP_SECONDS_MS: Final = 18_000
 _GPS_TIME_CUTOFF_MS: Final = 1_577_836_800_000  # 2020-01-01 in Unix ms
+_SECONDS_CUTOFF: Final = 100_000_000_000
 
 
 def _gnss_unix_ms(time: int) -> int:
     """A GNSS fix time as Unix epoch milliseconds."""
+    if 0 < time < _SECONDS_CUTOFF:
+        time *= 1000
     if 0 < time < _GPS_TIME_CUTOFF_MS:
         return time + _GPS_EPOCH_OFFSET_MS - _GPS_LEAP_SECONDS_MS
     return time
diff --git a/src/rivian/parallax/proto/dynamics.proto b/src/rivian/parallax/proto/dynamics.proto
index 707d5e4..1a9731c 100644
--- a/src/rivian/parallax/proto/dynamics.proto
+++ b/src/rivian/parallax/proto/dynamics.proto
@@ -55,7 +55,7 @@ message Gnss {
   float position_vertical_error = 7;   // meters
   float speed_error = 8;               // m/s
   float bearing_error = 9;             // degrees
-  int64 time = 10; // epoch ms (Unix, or GPS on some vehicles); the whole fix
+  int64 time = 10; // Unix ms, Unix seconds or GPS ms, by vehicle; the whole fix
 }
 
 // dynamics.vehicle.location
diff --git a/tests/parallax/test_dynamics.py b/tests/parallax/test_dynamics.py
index a88e7fa..e49034a 100644
--- a/tests/parallax/test_dynamics.py
+++ b/tests/parallax/test_dynamics.py
@@ -52,6 +52,15 @@ def test_gnss_gps_time() -> None:
     assert result["gnssTimeStamp"] == epoch(1790553428211)
 
 
+def test_gnss_unix_seconds() -> None:
+    """A fix time in Unix seconds is converted to milliseconds."""
+    result = decode(
+        "dynamics.vehicle.gnss", dynamics.Gnss(latitude=1.0, time=1794604023)
+    )
+    assert result["gnssTimeStamp"] == epoch(1794604023000)
+    assert result["gnssLocation"]["timeStamp"] == epoch(1794604023000)
+
+
 def test_gnss_empty() -> None:
     """An empty payload has no fix, so nothing is reported."""
     assert decode("dynamics.vehicle.gnss") == {}