diff --git a/src/ashtech.cpp b/src/ashtech.cpp
index 859e91d..1a23598 100644
--- a/src/ashtech.cpp
+++ b/src/ashtech.cpp
@@ -137,34 +137,16 @@ int GPSDriverAshtech::handleMessage(int len)
 		timeinfo.tm_sec = int(ashtech_sec);
 		timeinfo.tm_isdst = 0;
 
-#ifndef NO_MKTIME
 		time_t epoch = mktime(&timeinfo);
 
 		if (epoch > GPS_EPOCH_SECS) {
 			uint64_t usecs = static_cast<uint64_t>((ashtech_sec - static_cast<uint64_t>(ashtech_sec))) * 1000000;
-
-			// FMUv2+ boards have a hardware RTC, but GPS helps us to configure it
-			// and control its drift. Since we rely on the HRT for our monotonic
-			// clock, updating it from time to time is safe.
-
-			timespec ts{};
-			ts.tv_sec = epoch;
-			ts.tv_nsec = usecs * 1000;
-
-			setClock(ts);
-
 			_gps_position->time_utc_usec = static_cast<uint64_t>(epoch) * 1000000ULL;
 			_gps_position->time_utc_usec += usecs;
 
 		} else {
 			_gps_position->time_utc_usec = 0;
 		}
-
-#else
-		_gps_position->time_utc_usec = 0;
-#endif
-
-		_last_timestamp_time = gps_absolute_time();
 	}
 
 	else if ((memcmp(_rx_buffer + 3, "GGA,", 3) == 0) && (uiCalcComma == 14) && !_got_pashr_pos_message) {
@@ -262,7 +244,7 @@ int GPSDriverAshtech::handleMessage(int len)
 			_gps_position->fix_type = 3 + fix_quality - 1;
 		}
 
-		_gps_position->timestamp = gps_absolute_time();
+		_gps_position->timestamp_sample = gps_absolute_time();
 
 		_gps_position->vel_m_s = 0;                                  /**< GPS ground speed (m/s) */
 		_gps_position->vel_n_m_s = 0;                                /**< GPS ground speed in m/s */
@@ -444,7 +426,7 @@ int GPSDriverAshtech::handleMessage(int len)
 			}
 		}
 
-		_gps_position->timestamp = gps_absolute_time();
+		_gps_position->timestamp_sample = gps_absolute_time();
 
 		float track_rad = static_cast<float>(track_true) * M_PI_F / 180.0f;
 
@@ -705,11 +687,6 @@ int GPSDriverAshtech::handleMessage(int len)
 
 	}
 
-	if (ret == 1) {
-		_gps_position->timestamp_time_relative = (int32_t)(_last_timestamp_time - _gps_position->timestamp);
-	}
-
-
 	// handle survey-in status update
 	if (_survey_in_start != 0) {
 		const gps_abstime now = gps_absolute_time();
diff --git a/src/ashtech.h b/src/ashtech.h
index 2db2925..abb9f03 100644
--- a/src/ashtech.h
+++ b/src/ashtech.h
@@ -128,7 +128,6 @@ class GPSDriverAshtech : public GPSBaseStationSupport
 
 	uint8_t _rx_buffer[ASHTECH_RECV_BUFFER_SIZE];
 	uint16_t _rx_buffer_bytes{};
-	uint64_t _last_timestamp_time{0};
 
 	float _heading_offset;
 
diff --git a/src/emlid_reach.cpp b/src/emlid_reach.cpp
index 75f774a..1370973 100644
--- a/src/emlid_reach.cpp
+++ b/src/emlid_reach.cpp
@@ -282,7 +282,7 @@ GPSDriverEmlidReach::handleErbSentence()
 
 	} else if (_erb_buff.header.id == ERB_ID_GEODIC_POSITION) {
 
-		_gps_position->timestamp = gps_absolute_time();
+		_gps_position->timestamp_sample = gps_absolute_time();
 
 		_last_POS_timeGPS = _erb_buff.payload.geodic_position.timeGPS;
 		_gps_position->lon = round(_erb_buff.payload.geodic_position.longitude * 1e7);
diff --git a/src/femtomes.cpp b/src/femtomes.cpp
index 71c7da8..0184851 100644
--- a/src/femtomes.cpp
+++ b/src/femtomes.cpp
@@ -114,7 +114,6 @@ int GPSDriverFemto::handleMessage(int len)
 		_gps_position->vel_e_m_s = _femto_uav_gps.vel_e_m_s;
 		_gps_position->vel_d_m_s = _femto_uav_gps.vel_d_m_s;
 		_gps_position->cog_rad = _femto_uav_gps.cog_rad;
-		_gps_position->timestamp_time_relative = _femto_uav_gps.timestamp_time_relative;
 		_gps_position->fix_type = _femto_uav_gps.fix_type;
 		_gps_position->vel_ned_valid = _femto_uav_gps.vel_ned_valid;
 		_gps_position->satellites_used = _femto_uav_gps.satellites_used;
@@ -134,7 +133,7 @@ int GPSDriverFemto::handleMessage(int len)
 			_gps_position->heading = NAN;
 		}
 
-		_gps_position->timestamp = gps_absolute_time();
+		_gps_position->timestamp_sample = gps_absolute_time();
 
 		ret = 1;
 
diff --git a/src/femtomes.h b/src/femtomes.h
index 27d24b0..76d4623 100644
--- a/src/femtomes.h
+++ b/src/femtomes.h
@@ -66,7 +66,6 @@ typedef struct {
 	float 		vel_e_m_s;		/** GPS East velocity, (metres/sec)*/
 	float 		vel_d_m_s;		/** GPS Down velocity, (metres/sec)*/
 	float 		cog_rad;		/** Course over ground (NOT heading, but direction of movement), -PI..PI, (radians)*/
-	int32_t 	timestamp_time_relative;/** timestamp + timestamp_time_relative = Time of the UTC timestamp since system start, (microseconds)*/
 	float 		heading;		/** heading angle of XYZ body frame rel to NED. Set to NaN if not available and updated (used for dual antenna GPS), (rad, [-PI, PI])*/
 	uint8_t 	fix_type;		/** 0-1: no fix, 2: 2D fix, 3: 3D fix, 4: RTCM code differential, 5: Real-Time Kinematic, float, 6: Real-Time Kinematic, fixed, 8: Extrapolated. Some applications will not use the value of this field unless it is at least two, so always correctly fill in the fix.*/
 	bool 		vel_ned_valid;		/** True if NED velocity is valid*/
diff --git a/src/gps_helper.h b/src/gps_helper.h
index dc15491..79a036e 100644
--- a/src/gps_helper.h
+++ b/src/gps_helper.h
@@ -93,14 +93,6 @@ enum class GPSCallbackType {
 	 * return: ignored
 	 */
 	surveyInStatus,
-
-	/**
-	 * can be used to set the current clock accurately
-	 * data1: pointer to a timespec struct
-	 * data2: ignored
-	 * return: ignored
-	 */
-	setClock,
 };
 
 enum class GPSRestartType {
@@ -271,11 +263,6 @@ class GPSHelper
 		_callback(GPSCallbackType::gotRTCMMessage, buf, buf_length, _callback_user);
 	}
 
-	void setClock(timespec &t)
-	{
-		_callback(GPSCallbackType::setClock, &t, 0, _callback_user);
-	}
-
 	/**
 	 * Convert an ECEF (Earth Centered Earth Fixed) coordinate to LLA WGS84 (Lat, Lon, Alt).
 	 * Ported from: https://stackoverflow.com/a/25428344
diff --git a/src/mtk.cpp b/src/mtk.cpp
index 11ac27e..4c253f9 100644
--- a/src/mtk.cpp
+++ b/src/mtk.cpp
@@ -264,21 +264,9 @@ GPSDriverMTK::handleMessage(gps_mtk_packet_t &packet)
 
 	timeinfo.tm_isdst = 0;
 
-#ifndef NO_MKTIME
-
 	time_t epoch = mktime(&timeinfo);
 
 	if (epoch > GPS_EPOCH_SECS) {
-		// FMUv2+ boards have a hardware RTC, but GPS helps us to configure it
-		// and control its drift. Since we rely on the HRT for our monotonic
-		// clock, updating it from time to time is safe.
-
-		timespec ts{};
-		ts.tv_sec = epoch;
-		ts.tv_nsec = timeinfo_conversion_temp * 1000000ULL;
-
-		setClock(ts);
-
 		_gps_position->time_utc_usec = static_cast<uint64_t>(epoch) * 1000000ULL;
 		_gps_position->time_utc_usec += timeinfo_conversion_temp * 1000ULL;
 
@@ -286,12 +274,7 @@ GPSDriverMTK::handleMessage(gps_mtk_packet_t &packet)
 		_gps_position->time_utc_usec = 0;
 	}
 
-#else
-	_gps_position->time_utc_usec = 0;
-#endif
-
-	_gps_position->timestamp = gps_absolute_time();
-	_gps_position->timestamp_time_relative = 0;
+	_gps_position->timestamp_sample = gps_absolute_time();
 
 	// Position and velocity update always at the same time
 	_rate_count_vel++;
diff --git a/src/nmea.cpp b/src/nmea.cpp
index 5067c97..409a7ba 100644
--- a/src/nmea.cpp
+++ b/src/nmea.cpp
@@ -142,10 +142,8 @@ int GPSDriverNMEA::handleMessage(int len)
 		int utc_minute = static_cast<int>((utc_time - utc_hour * 10000) / 100);
 		double utc_sec = static_cast<double>(utc_time - utc_hour * 10000 - utc_minute * 100);
 
-		/*
-		* convert to unix timestamp
-		*/
-		struct tm timeinfo = {};
+		// convert to unix timestamp
+		struct tm timeinfo {};
 		timeinfo.tm_year = year - 1900;
 		timeinfo.tm_mon = month - 1;
 		timeinfo.tm_mday = day;
@@ -154,24 +152,11 @@ int GPSDriverNMEA::handleMessage(int len)
 		timeinfo.tm_sec = int(utc_sec);
 		timeinfo.tm_isdst = 0;
 
-#ifndef NO_MKTIME
 		time_t epoch = mktime(&timeinfo);
 
 		if (epoch > GPS_EPOCH_SECS) {
 			uint64_t usecs = static_cast<uint64_t>((utc_sec - static_cast<uint64_t>(utc_sec)) * 1000000);
 
-			// FMUv2+ boards have a hardware RTC, but GPS helps us to configure it
-			// and control its drift. Since we rely on the HRT for our monotonic
-			// clock, updating it from time to time is safe.
-
-			if (!_clock_set) {
-				timespec ts{};
-				ts.tv_sec = epoch;
-				ts.tv_nsec = usecs * 1000;
-				setClock(ts);
-				_clock_set = true;
-			}
-
 			_gps_position->time_utc_usec = static_cast<uint64_t>(epoch) * 1000000ULL;
 			_gps_position->time_utc_usec += usecs;
 
@@ -179,11 +164,8 @@ int GPSDriverNMEA::handleMessage(int len)
 			_gps_position->time_utc_usec = 0;
 		}
 
-#else
-		_gps_position->time_utc_usec = 0;
-#endif
 		_TIME_received = true;
-		_gps_position->timestamp = gps_absolute_time();
+		_gps_position->timestamp_sample = gps_absolute_time();
 
 	} else if ((memcmp(_rx_buffer + 3, "GGA,", 4) == 0) && (uiCalcComma >= 14)) {
 		/*
@@ -300,7 +282,7 @@ int GPSDriverNMEA::handleMessage(int len)
 		_FIX_received = true;
 
 		_gps_position->c_variance_rad = 0.1f;
-		_gps_position->timestamp = gps_absolute_time();
+		_gps_position->timestamp_sample = gps_absolute_time();
 
 	} else if (memcmp(_rx_buffer + 3, "HDT,", 4) == 0 && uiCalcComma == 2) {
 		/*
@@ -506,13 +488,12 @@ int GPSDriverNMEA::handleMessage(int len)
 		_gps_position->vel_ned_valid = true; /**< Flag to indicate if NED speed is valid */
 		_gps_position->c_variance_rad = 0.1f;
 		_gps_position->s_variance_m_s = 0;
-		_gps_position->timestamp = gps_absolute_time();
-		_last_timestamp_time = gps_absolute_time();
+		_gps_position->timestamp_sample = gps_absolute_time();
 
 		/*
 		 * convert to unix timestamp
 		 */
-		struct tm timeinfo = {};
+		struct tm timeinfo {};
 		timeinfo.tm_year = nmea_year + 100;
 		timeinfo.tm_mon = nmea_mth - 1;
 		timeinfo.tm_mday = nmea_day;
@@ -521,24 +502,10 @@ int GPSDriverNMEA::handleMessage(int len)
 		timeinfo.tm_sec = int(utc_sec);
 		timeinfo.tm_isdst = 0;
 
-#ifndef NO_MKTIME
 		time_t epoch = mktime(&timeinfo);
 
 		if (epoch > GPS_EPOCH_SECS) {
 			uint64_t usecs = static_cast<uint64_t>((utc_sec - static_cast<uint64_t>(utc_sec)) * 1000000);
-
-			// FMUv2+ boards have a hardware RTC, but GPS helps us to configure it
-			// and control its drift. Since we rely on the HRT for our monotonic
-			// clock, updating it from time to time is safe.
-			if (!_clock_set) {
-				timespec ts{};
-				ts.tv_sec = epoch;
-				ts.tv_nsec = usecs * 1000;
-
-				setClock(ts);
-				_clock_set = true;
-			}
-
 			_gps_position->time_utc_usec = static_cast<uint64_t>(epoch) * 1000000ULL;
 			_gps_position->time_utc_usec += usecs;
 
@@ -546,10 +513,6 @@ int GPSDriverNMEA::handleMessage(int len)
 			_gps_position->time_utc_usec = 0;
 		}
 
-#else
-		_gps_position->time_utc_usec = 0;
-#endif
-
 		if (!_POS_received && (_last_POS_timeUTC < utc_time)) {
 			_last_POS_timeUTC = utc_time;
 			_POS_received = true;
@@ -859,8 +822,6 @@ int GPSDriverNMEA::handleMessage(int len)
 
 	if (_VEL_received && _POS_received) {
 		ret = 1;
-		_gps_position->timestamp_time_relative = (int32_t)(_last_timestamp_time - _gps_position->timestamp);
-		_clock_set = false;
 		_VEL_received = false;
 		_POS_received = false;
 		_rate_count_vel++;
diff --git a/src/nmea.h b/src/nmea.h
index e0bd13d..ccd06d3 100644
--- a/src/nmea.h
+++ b/src/nmea.h
@@ -90,7 +90,6 @@ class GPSDriverNMEA : public GPSHelper
 	double _last_POS_timeUTC{0};
 	double _last_VEL_timeUTC{0};
 	double _last_FIX_timeUTC{0};
-	uint64_t _last_timestamp_time{0};
 
 	uint8_t _sat_num_gga{0};
 	uint8_t _sat_num_gns{0};
@@ -101,9 +100,7 @@ class GPSDriverNMEA : public GPSHelper
 	uint8_t _sat_num_gbgsv{0};
 	uint8_t _sat_num_bdgsv{0};
 
-	bool _clock_set {false};
-
-//  check if we got all basic essential packages we need
+	//  check if we got all basic essential packages we need
 	bool _TIME_received{false};
 	bool _POS_received{false};
 	bool _ALT_received{false};
diff --git a/src/sbf.cpp b/src/sbf.cpp
index a05e22f..10ca51c 100644
--- a/src/sbf.cpp
+++ b/src/sbf.cpp
@@ -387,8 +387,6 @@ int    // 0 = no message handled, 1 = message handled, 2 = sat info message hand
 GPSDriverSBF::payloadRxDone()
 {
 	int ret = 0;
-	struct tm timeinfo;
-	time_t epoch;
 
 	if (_buf.length <= 4 || _buf.crc16 != crc16(reinterpret_cast<uint8_t *>(&_buf) + 4, _buf.length - 4)) {
 		return 1;
@@ -474,10 +472,9 @@ GPSDriverSBF::payloadRxDone()
 		}
 
 		_gps_position->time_utc_usec = 0;
-#ifndef NO_MKTIME
-		/* convert to unix timestamp */
-		memset(&timeinfo, 0, sizeof(timeinfo));
 
+		/* convert to unix timestamp */
+		struct tm timeinfo {};
 		timeinfo.tm_year = 1980 - 1900;
 		timeinfo.tm_mon = 0;
 		timeinfo.tm_mday = 6 + _buf.WNc * 7;
@@ -485,26 +482,14 @@ GPSDriverSBF::payloadRxDone()
 		timeinfo.tm_min = 0;
 		timeinfo.tm_sec = _buf.TOW / 1000;
 
-		epoch = mktime(&timeinfo);
+		time_t epoch = mktime(&timeinfo);
 
 		if (epoch > GPS_EPOCH_SECS) {
-			// FMUv2+ boards have a hardware RTC, but GPS helps us to configure it
-			// and control its drift. Since we rely on the HRT for our monotonic
-			// clock, updating it from time to time is safe.
-
-			timespec ts;
-			memset(&ts, 0, sizeof(ts));
-			ts.tv_sec = epoch;
-			ts.tv_nsec = (_buf.TOW % 1000) * 1000 * 1000;
-			setClock(ts);
-
 			_gps_position->time_utc_usec = static_cast<uint64_t>(epoch) * 1000000ULL;
 			_gps_position->time_utc_usec += (_buf.TOW % 1000) * 1000;
 		}
 
-#endif
-		_gps_position->timestamp = gps_absolute_time();
-		_last_timestamp_time = _gps_position->timestamp;
+		_gps_position->timestamp_sample = gps_absolute_time();
 		_rate_count_vel++;
 		_rate_count_lat_lon++;
 		ret |= (_msg_status == 7) ? 1 : 0;
@@ -536,10 +521,6 @@ GPSDriverSBF::payloadRxDone()
 		break;
 	}
 
-	if (ret > 0) {
-		_gps_position->timestamp_time_relative = static_cast<int32_t>(_last_timestamp_time - _gps_position->timestamp);
-	}
-
 	if (ret == 1) {
 		_msg_status &= ~1;
 	}
diff --git a/src/sbf.h b/src/sbf.h
index 8699217..fad56ba 100644
--- a/src/sbf.h
+++ b/src/sbf.h
@@ -356,7 +356,6 @@ class GPSDriverSBF : public GPSBaseStationSupport
 	sensor_gps_s *_gps_position { nullptr };
 	satellite_info_s *_satellite_info { nullptr };
 	uint8_t _dynamic_model{ 7 };
-	uint64_t _last_timestamp_time { 0 };
 	bool _configured { false };
 	uint8_t _msg_status { 0 };
 	sbf_decode_state_t _decode_state { SBF_DECODE_SYNC1 };
diff --git a/src/ubx.cpp b/src/ubx.cpp
index 5109e9e..9d724a4 100644
--- a/src/ubx.cpp
+++ b/src/ubx.cpp
@@ -337,6 +337,8 @@ GPSDriverUBX::configure(unsigned &baudrate, const GPSConfig &config)
 		ret = configureDevicePreV27(config.gnss_systems);
 	}
 
+	_baudrate = baudrate; // store final baudrate
+
 	if (ret != 0) {
 		return ret;
 	}
@@ -1236,6 +1238,22 @@ GPSDriverUBX::payloadRxInit()
 
 		} else if (!_use_nav_pvt) {
 			_rx_state = UBX_RXMSG_DISABLE;        // disable if not using NAV-PVT
+
+		} else {
+			_gps_position->timestamp_sample = gps_absolute_time();
+
+			// adjust timestamp sample to account for transfer time
+			if (_baudrate != 0) {
+				float character_rate = _baudrate / 10; // 10 bits per character
+				float bytes_per_s = character_rate / 8; // 8 characters per byte
+				double transit_time_s = _rx_payload_length / bytes_per_s;
+				uint64_t transit_time_us = transit_time_s * 1e6;
+
+				//printf("baudrate: %d, transit time %.6f s (%llu) SZ:%d\n", _baudrate, transit_time_s, transit_time_us, _rx_payload_length);
+				if (_gps_position->timestamp_sample > transit_time_us) {
+					_gps_position->timestamp_sample -= transit_time_us;
+				}
+			}
 		}
 
 		break;
@@ -1259,6 +1277,9 @@ GPSDriverUBX::payloadRxInit()
 
 		} else if (_use_nav_pvt) {
 			_rx_state = UBX_RXMSG_DISABLE;        // disable if using NAV-PVT instead
+
+		} else {
+			_gps_position->timestamp_sample = gps_absolute_time();
 		}
 
 		break;
@@ -1272,6 +1293,9 @@ GPSDriverUBX::payloadRxInit()
 
 		} else if (_use_nav_pvt) {
 			_rx_state = UBX_RXMSG_DISABLE;        // disable if using NAV-PVT instead
+
+		} else {
+			_gps_position->timestamp_sample = gps_absolute_time();
 		}
 
 		break;
@@ -1805,6 +1829,7 @@ GPSDriverUBX::payloadRxDone()
 		if ((_buf.payload_rx_nav_pvt.valid & UBX_RX_NAV_PVT_VALID_VALIDDATE)
 		    && (_buf.payload_rx_nav_pvt.valid & UBX_RX_NAV_PVT_VALID_VALIDTIME)
 		    && (_buf.payload_rx_nav_pvt.valid & UBX_RX_NAV_PVT_VALID_FULLYRESOLVED)) {
+
 			/* convert to unix timestamp */
 			tm timeinfo{};
 			timeinfo.tm_year	= _buf.payload_rx_nav_pvt.year - 1900;
@@ -1814,35 +1839,17 @@ GPSDriverUBX::payloadRxDone()
 			timeinfo.tm_min		= _buf.payload_rx_nav_pvt.min;
 			timeinfo.tm_sec		= _buf.payload_rx_nav_pvt.sec;
 
-#ifndef NO_MKTIME
 			time_t epoch = mktime(&timeinfo);
 
 			if (epoch > GPS_EPOCH_SECS) {
-				// FMUv2+ boards have a hardware RTC, but GPS helps us to configure it
-				// and control its drift. Since we rely on the HRT for our monotonic
-				// clock, updating it from time to time is safe.
-
-				timespec ts{};
-				ts.tv_sec = epoch;
-				ts.tv_nsec = _buf.payload_rx_nav_pvt.nano;
-
-				setClock(ts);
-
 				_gps_position->time_utc_usec = static_cast<uint64_t>(epoch) * 1000000ULL;
 				_gps_position->time_utc_usec += _buf.payload_rx_nav_pvt.nano / 1000;
 
 			} else {
 				_gps_position->time_utc_usec = 0;
 			}
-
-#else
-			_gps_position->time_utc_usec = 0;
-#endif
 		}
 
-		_gps_position->timestamp = gps_absolute_time();
-		_last_timestamp_time = _gps_position->timestamp;
-
 		_rate_count_vel++;
 		_rate_count_lat_lon++;
 
@@ -1878,8 +1885,6 @@ GPSDriverUBX::payloadRxDone()
 		_gps_position->epv	= static_cast<float>(_buf.payload_rx_nav_posllh.vAcc) * 1e-3f; // from mm to m
 		_gps_position->alt_ellipsoid = _buf.payload_rx_nav_posllh.height;
 
-		_gps_position->timestamp = gps_absolute_time();
-
 		_rate_count_lat_lon++;
 		_got_posllh = true;
 
@@ -1907,6 +1912,7 @@ GPSDriverUBX::payloadRxDone()
 
 	case UBX_MSG_NAV_TIMEUTC:
 		UBX_TRACE_RXMSG("Rx NAV-TIMEUTC");
+		fprintf(stderr, "UBX_MSG_NAV_TIMEUTC\n");
 
 		if (_buf.payload_rx_nav_timeutc.valid & UBX_RX_NAV_TIMEUTC_VALID_VALIDUTC) {
 			// convert to unix timestamp
@@ -1918,36 +1924,19 @@ GPSDriverUBX::payloadRxDone()
 			timeinfo.tm_min		= _buf.payload_rx_nav_timeutc.min;
 			timeinfo.tm_sec		= _buf.payload_rx_nav_timeutc.sec;
 			timeinfo.tm_isdst	= 0;
-#ifndef NO_MKTIME
+
 			time_t epoch = mktime(&timeinfo);
 
 			// only set the time if it makes sense
-
 			if (epoch > GPS_EPOCH_SECS) {
-				// FMUv2+ boards have a hardware RTC, but GPS helps us to configure it
-				// and control its drift. Since we rely on the HRT for our monotonic
-				// clock, updating it from time to time is safe.
-
-				timespec ts{};
-				ts.tv_sec = epoch;
-				ts.tv_nsec = _buf.payload_rx_nav_timeutc.nano;
-
-				setClock(ts);
-
 				_gps_position->time_utc_usec = static_cast<uint64_t>(epoch) * 1000000ULL;
 				_gps_position->time_utc_usec += _buf.payload_rx_nav_timeutc.nano / 1000;
 
 			} else {
 				_gps_position->time_utc_usec = 0;
 			}
-
-#else
-			_gps_position->time_utc_usec = 0;
-#endif
 		}
 
-		_last_timestamp_time = gps_absolute_time();
-
 		ret = 1;
 		break;
 
@@ -2114,10 +2103,6 @@ GPSDriverUBX::payloadRxDone()
 		break;
 	}
 
-	if (ret > 0) {
-		_gps_position->timestamp_time_relative = (int32_t)(_last_timestamp_time - _gps_position->timestamp);
-	}
-
 	return ret;
 }
 
diff --git a/src/ubx.h b/src/ubx.h
index d51f73d..2c56ded 100644
--- a/src/ubx.h
+++ b/src/ubx.h
@@ -1097,8 +1097,6 @@ class GPSDriverUBX : public GPSBaseStationSupport
 
 	uint32_t _ubx_version{0};
 
-	uint64_t _last_timestamp_time{0};
-
 	Board _board{Board::unknown};
 
 	OutputMode _output_mode{OutputMode::GPS};
@@ -1107,6 +1105,8 @@ class GPSDriverUBX : public GPSBaseStationSupport
 
 	const UBXMode _mode;
 	const float _heading_offset;
+
+	unsigned _baudrate{0};
 };