diff --git a/selfdrive/locationd/locationd.cc b/selfdrive/locationd/locationd.cc
index 9608f4003..e156af5d6 100755
--- a/selfdrive/locationd/locationd.cc
+++ b/selfdrive/locationd/locationd.cc
@@ -20,6 +20,11 @@ const double VALID_POS_STD = 50.0; // m
 const double MAX_RESET_TRACKER = 5.0;
 const double SANE_GPS_UNCERTAINTY = 1500.0; // m
 
+// TODO: GPS sensor time offsets are empirically calculated
+// They should be replaced with synced time from a real clock
+const double GPS_LOCATION_SENSOR_TIME_OFFSET = 0.630; // s
+const double GPS_LOCATION_EXTERNAL_SENSOR_TIME_OFFSET = 0.095; // s
+
 static VectorXd floatlist2vector(const capnp::List<float, capnp::Kind::PRIMITIVE>::Reader& floatlist) {
   VectorXd res(floatlist.size());
   for (int i = 0; i < floatlist.size(); i++) {
@@ -257,7 +262,7 @@ void Localizer::input_fake_gps_observations(double current_time) {
   this->kf->predict_and_observe(current_time, OBSERVATION_ECEF_VEL, { ecef_vel }, { ecef_vel_R });
 }
 
-void Localizer::handle_gps(double current_time, const cereal::GpsLocationData::Reader& log) {
+void Localizer::handle_gps(double current_time, const cereal::GpsLocationData::Reader& log, const double sensor_time_offset) {
   // ignore the message if the fix is invalid
   bool gps_invalid_flag = (log.getFlags() % 2 == 0);
   bool gps_unreasonable = (Vector2d(log.getAccuracy(), log.getVerticalAccuracy()).norm() >= SANE_GPS_UNCERTAINTY);
@@ -265,13 +270,15 @@ void Localizer::handle_gps(double current_time, const cereal::GpsLocationData::R
   bool gps_lat_lng_alt_insane = ((std::abs(log.getLatitude()) > 90) || (std::abs(log.getLongitude()) > 180) || (std::abs(log.getAltitude()) > ALTITUDE_SANITY_CHECK));
   bool gps_vel_insane = (floatlist2vector(log.getVNED()).norm() > TRANS_SANITY_CHECK);
 
-  if (gps_invalid_flag || gps_unreasonable || gps_accuracy_insane || gps_lat_lng_alt_insane || gps_vel_insane){
+  if (gps_invalid_flag || gps_unreasonable || gps_accuracy_insane || gps_lat_lng_alt_insane || gps_vel_insane) {
     this->determine_gps_mode(current_time);
     return;
   }
+  
+  double sensor_time = current_time - sensor_time_offset;
 
   // Process message
-  this->last_gps_fix = current_time;
+  this->last_gps_fix = sensor_time;
   this->gps_mode = true;
   Geodetic geodetic = { log.getLatitude(), log.getLongitude(), log.getAltitude() };
   this->converter = std::make_unique<LocalCoord>(geodetic);
@@ -300,14 +307,14 @@ void Localizer::handle_gps(double current_time, const cereal::GpsLocationData::R
   if (ecef_vel.norm() > 5.0 && orientation_error.norm() > 1.0) {
     LOGE("Locationd vs ubloxLocation orientation difference too large, kalman reset");
     this->reset_kalman(NAN, initial_pose_ecef_quat, ecef_pos, ecef_vel, ecef_pos_R, ecef_vel_R);
-    this->kf->predict_and_observe(current_time, OBSERVATION_ECEF_ORIENTATION_FROM_GPS, { initial_pose_ecef_quat });
+    this->kf->predict_and_observe(sensor_time, OBSERVATION_ECEF_ORIENTATION_FROM_GPS, { initial_pose_ecef_quat });
   } else if (gps_est_error > 100.0) {
     LOGE("Locationd vs ubloxLocation position difference too large, kalman reset");
     this->reset_kalman(NAN, initial_pose_ecef_quat, ecef_pos, ecef_vel, ecef_pos_R, ecef_vel_R);
   }
 
-  this->kf->predict_and_observe(current_time, OBSERVATION_ECEF_POS, { ecef_pos }, { ecef_pos_R });
-  this->kf->predict_and_observe(current_time, OBSERVATION_ECEF_VEL, { ecef_vel }, { ecef_vel_R });
+  this->kf->predict_and_observe(sensor_time, OBSERVATION_ECEF_POS, { ecef_pos }, { ecef_pos_R });
+  this->kf->predict_and_observe(sensor_time, OBSERVATION_ECEF_VEL, { ecef_vel }, { ecef_vel_R });
 }
 
 void Localizer::handle_car_state(double current_time, const cereal::CarState::Reader& log) {
@@ -443,9 +450,9 @@ void Localizer::handle_msg(const cereal::Event::Reader& log) {
   } else if (log.isGyroscope()) {
     this->handle_sensor(t, log.getGyroscope());
   } else if (log.isGpsLocation()) {
-    this->handle_gps(t, log.getGpsLocation());
+    this->handle_gps(t, log.getGpsLocation(), GPS_LOCATION_SENSOR_TIME_OFFSET);
   } else if (log.isGpsLocationExternal()) {
-    this->handle_gps(t, log.getGpsLocationExternal());
+    this->handle_gps(t, log.getGpsLocationExternal(), GPS_LOCATION_EXTERNAL_SENSOR_TIME_OFFSET);
   } else if (log.isCarState()) {
     this->handle_car_state(t, log.getCarState());
   } else if (log.isCameraOdometry()) {
@@ -497,9 +504,8 @@ int Localizer::locationd_thread() {
   } else {
     gps_location_socket = "gpsLocation";
   }
-  const std::initializer_list<const char *> service_list = {gps_location_socket,
-    "cameraOdometry", "liveCalibration", "carState", "carParams",
-    "accelerometer", "gyroscope"};
+  const std::initializer_list<const char *> service_list = {gps_location_socket, "cameraOdometry", "liveCalibration", 
+                                                          "carState", "carParams", "accelerometer", "gyroscope"};
   PubMaster pm({"liveLocationKalman"});
 
   // TODO: remove carParams once we're always sending at 100Hz
diff --git a/selfdrive/locationd/locationd.h b/selfdrive/locationd/locationd.h
index b17ab04b2..280296b06 100755
--- a/selfdrive/locationd/locationd.h
+++ b/selfdrive/locationd/locationd.h
@@ -46,7 +46,7 @@ public:
   void handle_msg_bytes(const char *data, const size_t size);
   void handle_msg(const cereal::Event::Reader& log);
   void handle_sensor(double current_time, const cereal::SensorEventData::Reader& log);
-  void handle_gps(double current_time, const cereal::GpsLocationData::Reader& log);
+  void handle_gps(double current_time, const cereal::GpsLocationData::Reader& log, const double sensor_time_offset);
   void handle_car_state(double current_time, const cereal::CarState::Reader& log);
   void handle_cam_odo(double current_time, const cereal::CameraOdometry::Reader& log);
   void handle_live_calib(double current_time, const cereal::LiveCalibrationData::Reader& log);
diff --git a/selfdrive/locationd/models/live_kf.cc b/selfdrive/locationd/models/live_kf.cc
index 5ff0f2699..f8c03365e 100755
--- a/selfdrive/locationd/models/live_kf.cc
+++ b/selfdrive/locationd/models/live_kf.cc
@@ -44,7 +44,7 @@ LiveKalman::LiveKalman() {
   // init filter
   this->filter = std::make_shared<EKFSym>(this->name, get_mapmat(this->Q), get_mapvec(this->initial_x),
     get_mapmat(initial_P),  this->dim_state, this->dim_state_err, 0, 0, 0, std::vector<int>(),
-    std::vector<int>{3}, std::vector<std::string>(), 0.2);
+    std::vector<int>{3}, std::vector<std::string>(), 0.8);
 }
 
 void LiveKalman::init_state(VectorXd& state, VectorXd& covs_diag, double filter_time) {
diff --git a/selfdrive/locationd/test/test_locationd.py b/selfdrive/locationd/test/test_locationd.py
index e32861cfa..756953021 100755
--- a/selfdrive/locationd/test/test_locationd.py
+++ b/selfdrive/locationd/test/test_locationd.py
@@ -53,6 +53,7 @@ class TestLocationdProc(unittest.TestCase):
       msg.gpsLocationExternal.vNED = [0.0, 0.0, 0.0]
       msg.gpsLocationExternal.latitude = self.lat
       msg.gpsLocationExternal.longitude = self.lon
+      msg.gpsLocationExternal.unixTimestampMillis = t * 1e6
       msg.gpsLocationExternal.altitude = self.alt
     elif name == 'cameraOdometry':
       msg.cameraOdometry.rot = [0.0, 0.0, 0.0]
diff --git a/selfdrive/test/process_replay/ref_commit b/selfdrive/test/process_replay/ref_commit
index 4577d3cdd..e01fe2ac3 100644
--- a/selfdrive/test/process_replay/ref_commit
+++ b/selfdrive/test/process_replay/ref_commit
@@ -1 +1 @@
-27022484e3f4c0265ee7243154659b2697de3af7
\ No newline at end of file
+14bc91c326f75ce48337720668a1744184c46994
\ No newline at end of file