diff --git a/docs/changelog.md b/docs/changelog.md
index 6353d23ba..c958a70d0 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -70,6 +70,7 @@ SPDX-FileCopyrightText: 2011-2020 Carles Fernandez-Prades <carles.fernandez@cttc
 ### Improvements in Reliability:
 
 - Fixed a bug in GLONASS GNAV CRC computation.
+- Fixed a bug in GLONASS time year.
 - Fixed a possible buffer overflow in the generation of RTCM messages.
 - Fixed bugs which could cause a random crash on receiver stopping.
 
diff --git a/src/algorithms/PVT/libs/rinex_printer.cc b/src/algorithms/PVT/libs/rinex_printer.cc
index e5554116a..1b2ffd330 100644
--- a/src/algorithms/PVT/libs/rinex_printer.cc
+++ b/src/algorithms/PVT/libs/rinex_printer.cc
@@ -11982,6 +11982,23 @@ boost::posix_time::ptime Rinex_Printer::compute_UTC_time(const Glonass_Gnav_Ephe
     const double glot2utc = 3 * 3600;
     double obs_time_glot = 0.0;
     int32_t i = 0;
+    int J = 0;
+    if (eph.d_N_T >= 1 && eph.d_N_T <= 366)
+        {
+            J = 1;
+        }
+    else if (eph.d_N_T >= 367 && eph.d_N_T <= 731)
+        {
+            J = 2;
+        }
+    else if (eph.d_N_T >= 732 && eph.d_N_T <= 1096)
+        {
+            J = 3;
+        }
+    else if (eph.d_N_T >= 1097 && eph.d_N_T <= 1461)
+        {
+            J = 4;
+        }
 
     // Get observation time in nearly GLONASS time. Correction for leap seconds done at the end
     obs_time_glot = obs_time + glot2utc;
@@ -11991,7 +12008,7 @@ boost::posix_time::ptime Rinex_Printer::compute_UTC_time(const Glonass_Gnav_Ephe
 
     // Form date and time duration types
     const boost::posix_time::time_duration t1(0, 0, tod);
-    const boost::gregorian::date d1(eph.d_yr, 1, 1);
+    const boost::gregorian::date d1(eph.d_yr - J + 1.0, 1, 1);
     const boost::gregorian::days d2(eph.d_N_T - 1);
     const boost::posix_time::ptime glo_time(d1 + d2, t1);
 
@@ -12024,6 +12041,23 @@ double Rinex_Printer::get_leap_second(const Glonass_Gnav_Ephemeris& eph, const d
     double obs_time_glot = 0.0;
     int32_t i = 0;
     double leap_second = 0;
+    int J = 0;
+    if (eph.d_N_T >= 1 && eph.d_N_T <= 366)
+        {
+            J = 1;
+        }
+    else if (eph.d_N_T >= 367 && eph.d_N_T <= 731)
+        {
+            J = 2;
+        }
+    else if (eph.d_N_T >= 732 && eph.d_N_T <= 1096)
+        {
+            J = 3;
+        }
+    else if (eph.d_N_T >= 1097 && eph.d_N_T <= 1461)
+        {
+            J = 4;
+        }
 
     // Get observation time in nearly GLONASS time. Correction for leap seconds done at the end
     obs_time_glot = gps_obs_time + glot2utc;
@@ -12033,7 +12067,7 @@ double Rinex_Printer::get_leap_second(const Glonass_Gnav_Ephemeris& eph, const d
 
     // Form date and time duration types
     const boost::posix_time::time_duration t1(0, 0, tod);
-    const boost::gregorian::date d1(eph.d_yr, 1, 1);
+    const boost::gregorian::date d1(eph.d_yr - J + 1.0, 1, 1);
     const boost::gregorian::days d2(eph.d_N_T - 1);
     const boost::posix_time::ptime glo_time(d1 + d2, t1);
 
diff --git a/src/core/system_parameters/glonass_gnav_ephemeris.cc b/src/core/system_parameters/glonass_gnav_ephemeris.cc
index ee92c4c1f..c26d60128 100644
--- a/src/core/system_parameters/glonass_gnav_ephemeris.cc
+++ b/src/core/system_parameters/glonass_gnav_ephemeris.cc
@@ -27,11 +27,29 @@
 #include <string>
 
 
-boost::posix_time::ptime Glonass_Gnav_Ephemeris::compute_GLONASS_time(const double offset_time) const
+boost::posix_time::ptime Glonass_Gnav_Ephemeris::compute_GLONASS_time(double offset_time) const
 {
-    boost::posix_time::time_duration t(0, 0, offset_time + d_tau_c + d_tau_n);
-    boost::gregorian::date d1(d_yr, 1, 1);
-    boost::gregorian::days d2(d_N_T - 1);
+    int J = 0;
+    if (d_N_T >= 1 && d_N_T <= 366)
+        {
+            J = 1;
+        }
+    else if (d_N_T >= 367 && d_N_T <= 731)
+        {
+            J = 2;
+        }
+    else if (d_N_T >= 732 && d_N_T <= 1096)
+        {
+            J = 3;
+        }
+    else if (d_N_T >= 1097 && d_N_T <= 1461)
+        {
+            J = 4;
+        }
+
+    const boost::posix_time::time_duration t(0, 0, offset_time + d_tau_c + d_tau_n);
+    const boost::gregorian::date d1(d_yr - J + 1.0, 1, 1);
+    const boost::gregorian::days d2(d_N_T - 1);
     boost::posix_time::ptime glonass_time(d1 + d2, t);
 
     return glonass_time;
@@ -40,13 +58,29 @@ boost::posix_time::ptime Glonass_Gnav_Ephemeris::compute_GLONASS_time(const doub
 
 boost::posix_time::ptime Glonass_Gnav_Ephemeris::glot_to_utc(const double offset_time, const double glot2utc_corr) const
 {
-    double tod = 0.0;
-    double glot2utc = 3 * 3600;
+    const double glot2utc = 3 * 3600;
+    int J = 0;
+    if (d_N_T >= 1 && d_N_T <= 366)
+        {
+            J = 1;
+        }
+    else if (d_N_T >= 367 && d_N_T <= 731)
+        {
+            J = 2;
+        }
+    else if (d_N_T >= 732 && d_N_T <= 1096)
+        {
+            J = 3;
+        }
+    else if (d_N_T >= 1097 && d_N_T <= 1461)
+        {
+            J = 4;
+        }
 
-    tod = offset_time - glot2utc + glot2utc_corr + d_tau_n;
-    boost::posix_time::time_duration t(0, 0, tod);
-    boost::gregorian::date d1(d_yr, 1, 1);
-    boost::gregorian::days d2(d_N_T - 1);
+    const double tod = offset_time - glot2utc + glot2utc_corr + d_tau_n;
+    const boost::posix_time::time_duration t(0, 0, tod);
+    const boost::gregorian::date d1(d_yr - J + 1.0, 1, 1);
+    const boost::gregorian::days d2(d_N_T - 1);
     boost::posix_time::ptime utc_time(d1 + d2, t);
 
     return utc_time;
@@ -55,32 +89,48 @@ boost::posix_time::ptime Glonass_Gnav_Ephemeris::glot_to_utc(const double offset
 
 void Glonass_Gnav_Ephemeris::glot_to_gpst(double tod_offset, double glot2utc_corr, double glot2gpst_corr, int32_t* wn, double* tow) const
 {
-    double tod = 0.0;
-    double glot2utc = 3 * 3600;
+    const double glot2utc = 3 * 3600;
     double days = 0.0;
     double total_sec = 0.0;
     double sec_of_day = 0.0;
     int i = 0;
+    int J = 0;
+    if (d_N_T >= 1 && d_N_T <= 366)
+        {
+            J = 1;
+        }
+    else if (d_N_T >= 367 && d_N_T <= 731)
+        {
+            J = 2;
+        }
+    else if (d_N_T >= 732 && d_N_T <= 1096)
+        {
+            J = 3;
+        }
+    else if (d_N_T >= 1097 && d_N_T <= 1461)
+        {
+            J = 4;
+        }
 
-    boost::gregorian::date gps_epoch{1980, 1, 6};
+    const boost::gregorian::date gps_epoch{1980, 1, 6};
 
     // tk is relative to UTC(SU) + 3.00 hrs, so we need to convert to utc and add corrections
     // tk plus 10 sec is the true tod since get_TOW is called when in str5
-    tod = tod_offset - glot2utc;
+    const double tod = tod_offset - glot2utc;
 
-    boost::posix_time::time_duration t(0, 0, tod);
-    boost::gregorian::date d1(d_yr, 1, 1);
-    boost::gregorian::days d2(d_N_T - 1);
-    boost::posix_time::ptime utc_time(d1 + d2, t);
-    boost::gregorian::date utc_date = utc_time.date();
+    const boost::posix_time::time_duration t(0, 0, tod);
+    const boost::gregorian::date d1(d_yr - J + 1.0, 1, 1);
+    const boost::gregorian::days d2(d_N_T - 1);
+    const boost::posix_time::ptime utc_time(d1 + d2, t);
+    const boost::gregorian::date utc_date = utc_time.date();
     boost::posix_time::ptime gps_time;
 
     // Adjust for leap second correction
     for (i = 0; GLONASS_LEAP_SECONDS[i][0] > 0; i++)
         {
-            boost::posix_time::time_duration t3(GLONASS_LEAP_SECONDS[i][3], GLONASS_LEAP_SECONDS[i][4], GLONASS_LEAP_SECONDS[i][5]);
-            boost::gregorian::date d3(GLONASS_LEAP_SECONDS[i][0], GLONASS_LEAP_SECONDS[i][1], GLONASS_LEAP_SECONDS[i][2]);
-            boost::posix_time::ptime ls_time(d3, t3);
+            const boost::posix_time::time_duration t3(GLONASS_LEAP_SECONDS[i][3], GLONASS_LEAP_SECONDS[i][4], GLONASS_LEAP_SECONDS[i][5]);
+            const boost::gregorian::date d3(GLONASS_LEAP_SECONDS[i][0], GLONASS_LEAP_SECONDS[i][1], GLONASS_LEAP_SECONDS[i][2]);
+            const boost::posix_time::ptime ls_time(d3, t3);
             if (utc_time >= ls_time)
                 {
                     // We add the leap second when going from utc to gpst
@@ -90,7 +140,6 @@ void Glonass_Gnav_Ephemeris::glot_to_gpst(double tod_offset, double glot2utc_cor
         }
 
     // Total number of days
-    std::string fdat = boost::posix_time::to_simple_string(gps_time);
     days = static_cast<double>((utc_date - gps_epoch).days());
 
     // Total number of seconds
@@ -109,9 +158,8 @@ void Glonass_Gnav_Ephemeris::glot_to_gpst(double tod_offset, double glot2utc_cor
 
 double Glonass_Gnav_Ephemeris::check_t(double time)
 {
-    double corrTime;
-    double half_day = 43200.0;  // seconds
-    corrTime = time;
+    const double half_day = 43200.0;  // seconds
+    double corrTime = time;
     if (time > half_day)
         {
             corrTime = time - 2.0 * half_day;
@@ -128,8 +176,7 @@ double Glonass_Gnav_Ephemeris::check_t(double time)
 // 20.3.3.3.3.1 User Algorithm for SV Clock Correction.
 double Glonass_Gnav_Ephemeris::sv_clock_drift(double transmitTime, double timeCorrUTC)
 {
-    double dt;
-    dt = check_t(transmitTime - d_t_b);
+    const double dt = check_t(transmitTime - d_t_b);
     d_satClkDrift = -(d_tau_n + timeCorrUTC - d_gamma_n * dt);
     // Correct satellite group delay and missing relativistic term here
     // d_satClkDrift-=d_TGD;
diff --git a/src/core/system_parameters/glonass_gnav_ephemeris.h b/src/core/system_parameters/glonass_gnav_ephemeris.h
index cf85e4351..07cfd780b 100644
--- a/src/core/system_parameters/glonass_gnav_ephemeris.h
+++ b/src/core/system_parameters/glonass_gnav_ephemeris.h
@@ -24,6 +24,7 @@
 #define GNSS_SDR_GLONASS_GNAV_EPHEMERIS_H
 
 
+#include "glonass_gnav_utc_model.h"
 #include <boost/date_time/posix_time/ptime.hpp>  // for ptime
 #include <boost/serialization/nvp.hpp>
 #include <cstdint>
@@ -94,7 +95,7 @@ public:
      *  \brief Computes the GLONASS System Time and returns a boost::posix_time::ptime object
      * \ param offset_time Is the start of day offset to compute the time
      */
-    boost::posix_time::ptime compute_GLONASS_time(const double offset_time) const;
+    boost::posix_time::ptime compute_GLONASS_time(double offset_time) const;
 
     /*!
      * \brief Converts from GLONASST to UTC
diff --git a/src/tests/unit-tests/system-parameters/glonass_gnav_ephemeris_test.cc b/src/tests/unit-tests/system-parameters/glonass_gnav_ephemeris_test.cc
index aae70cf81..a62b3a924 100644
--- a/src/tests/unit-tests/system-parameters/glonass_gnav_ephemeris_test.cc
+++ b/src/tests/unit-tests/system-parameters/glonass_gnav_ephemeris_test.cc
@@ -51,6 +51,60 @@ TEST(GlonassGnavEphemerisTest, ComputeGlonassTime)
 }
 
 
+TEST(GlonassGnavEphemerisTest, ComputeGlonassTime2019)
+{
+    Glonass_Gnav_Ephemeris gnav_eph;
+    gnav_eph.d_yr = 2019;
+    gnav_eph.d_N_T = 1366;
+    boost::posix_time::time_duration t(0, 0, 7560);
+    boost::gregorian::date d(gnav_eph.d_yr, 1, 1);
+    boost::gregorian::days d2(gnav_eph.d_N_T);
+    d = d + d2;
+
+    boost::gregorian::date expected_gdate;
+    boost::posix_time::time_duration expected_gtime;
+
+    boost::posix_time::ptime gtime = gnav_eph.compute_GLONASS_time(7560);
+    expected_gdate = gtime.date();
+    expected_gtime = gtime.time_of_day();
+
+    // Perform assertions of decoded fields
+    ASSERT_TRUE(expected_gdate.year() - d.year() < FLT_EPSILON);
+    ASSERT_TRUE(expected_gdate.month() - d.month() < FLT_EPSILON);
+    ASSERT_TRUE(expected_gdate.day() - d.day() < FLT_EPSILON);
+    ASSERT_TRUE(expected_gtime.hours() - t.hours() < FLT_EPSILON);
+    ASSERT_TRUE(expected_gtime.minutes() - t.minutes() < FLT_EPSILON);
+    ASSERT_TRUE(expected_gtime.seconds() - t.seconds() < FLT_EPSILON);
+}
+
+
+TEST(GlonassGnavEphemerisTest, ComputeGlonassTime2020)
+{
+    Glonass_Gnav_Ephemeris gnav_eph;
+    gnav_eph.d_yr = 2020;
+    gnav_eph.d_N_T = 62;
+    boost::posix_time::time_duration t(0, 0, 7560);
+    boost::gregorian::date d(gnav_eph.d_yr, 1, 1);
+    boost::gregorian::days d2(gnav_eph.d_N_T);
+    d = d + d2;
+
+    boost::gregorian::date expected_gdate;
+    boost::posix_time::time_duration expected_gtime;
+
+    boost::posix_time::ptime gtime = gnav_eph.compute_GLONASS_time(7560);
+    expected_gdate = gtime.date();
+    expected_gtime = gtime.time_of_day();
+
+    // Perform assertions of decoded fields
+    ASSERT_TRUE(expected_gdate.year() - d.year() < FLT_EPSILON);
+    ASSERT_TRUE(expected_gdate.month() - d.month() < FLT_EPSILON);
+    ASSERT_TRUE(expected_gdate.day() - d.day() < FLT_EPSILON);
+    ASSERT_TRUE(expected_gtime.hours() - t.hours() < FLT_EPSILON);
+    ASSERT_TRUE(expected_gtime.minutes() - t.minutes() < FLT_EPSILON);
+    ASSERT_TRUE(expected_gtime.seconds() - t.seconds() < FLT_EPSILON);
+}
+
+
 /*!
  * \brief Testing conversion from GLONASST to GPST
  * \test Tests scenario for N_T when greater than 365 days. Possible values here from 1 to 365*4
@@ -127,3 +181,47 @@ TEST(GlonassGnavEphemerisTest, ConvertGlonassT2GpsT3)
     ASSERT_TRUE(week - true_week < FLT_EPSILON);
     ASSERT_TRUE(tow - true_tow < FLT_EPSILON);
 }
+
+
+TEST(GlonassGnavEphemerisTest, ConvertGlonassT2GpsT4)
+{
+    Glonass_Gnav_Ephemeris gnav_eph;
+    gnav_eph.d_yr = 2019;
+    gnav_eph.d_N_T = 1366;
+
+    double glo2utc = 3600 * 3;
+    double tod = 7560;
+    int week = 0.0;
+    double tow = 0.0;
+    double true_leap_sec = 18;
+    double true_week = 2072;
+    double true_tow = 447120 + true_leap_sec + tod;
+
+    gnav_eph.glot_to_gpst(tod + glo2utc, 0.0, 0.0, &week, &tow);
+
+    // Perform assertions of decoded fields
+    ASSERT_TRUE(week - true_week < FLT_EPSILON);
+    ASSERT_TRUE(tow - true_tow < FLT_EPSILON);
+}
+
+
+TEST(GlonassGnavEphemerisTest, ConvertGlonassT2GpsT5)
+{
+    Glonass_Gnav_Ephemeris gnav_eph;
+    gnav_eph.d_yr = 2020;
+    gnav_eph.d_N_T = 62;
+
+    double glo2utc = 3600 * 3;
+    double tod = 7560;
+    int week = 0.0;
+    double tow = 0.0;
+    double true_leap_sec = 18;
+    double true_week = 2095;
+    double true_tow = 259200 + true_leap_sec + tod;
+
+    gnav_eph.glot_to_gpst(tod + glo2utc, 0.0, 0.0, &week, &tow);
+
+    // Perform assertions of decoded fields
+    ASSERT_TRUE(week - true_week < FLT_EPSILON);
+    ASSERT_TRUE(tow - true_tow < FLT_EPSILON);
+}