diff --git a/cxx/CMakeLists.txt b/cxx/CMakeLists.txt
index f43994a..a23af11 100644
--- a/cxx/CMakeLists.txt
+++ b/cxx/CMakeLists.txt
@@ -120,7 +120,7 @@ set(MOUNT_SERVER_APP_SRC mount.h mount_state.h mount_server.cpp comm_server.h co
 set(MOUNT_SERVER_APP mount_server)
 add_executable(${MOUNT_SERVER_APP} ${MOUNT_SERVER_APP_SRC})
 # target_include_directories(${MOUNT_SERVER_APP} PUBLIC ${ERFA_INCLUDE_DIR})
-target_link_libraries(${MOUNT_SERVER_APP} ${CNTR_PROTO_LIB} spdlog::spdlog_header_only ${ERFA_LIB})
+target_link_libraries(${MOUNT_SERVER_APP} ${CNTR_PROTO_LIB} spdlog::spdlog_header_only ERFA_LIB)
 
 if (WITH_TESTS)
     set(CNTR_PROTO_TEST_APP cntr_proto_test)
@@ -133,6 +133,6 @@ if (WITH_TESTS)
     add_executable(${CFGFILE_TEST_APP} tests/configfile_test.cpp)
 
     set(ASTROM_TEST_APP astrom_test)
-    add_executable(${ASTROM_TEST_APP} tests/astrom_test.cpp
-        mcc_traits.h)
+    add_executable(${ASTROM_TEST_APP} tests/astrom_test.cpp)
+    target_link_libraries(${ASTROM_TEST_APP} ERFA_LIB)
 endif()
diff --git a/cxx/mount.h b/cxx/mount.h
index d97d773..f23a287 100644
--- a/cxx/mount.h
+++ b/cxx/mount.h
@@ -110,6 +110,8 @@ class MccMount : public utils::MccSpdlogLogger
 public:
     static constexpr MccMountType mountType = MOUNT_TYPE;
 
+    enum IersDatabaseType { IERS_DB_LEAPSECS, IERS_DB_EARTH_ORIENT };
+
     /*  mount main-cycle variable quantities (mount orientation)  */
     struct mount_orient_t {
         // time-related
@@ -162,23 +164,8 @@ public:
 
         logInfo("Load leap seconds and Earth orientation databases ...");
 
-        auto time_db_loader = [this](const std::string& filename, std::string_view type, auto& db) {
-            if (filename.empty()) {
-                logWarn("An empty {} filename! Skip and keep default values!", type);
-                return;
-            }
-
-            bool ok = db.load(filename);
-            if (!ok) {
-                logError("CANNOT parse {} file '{}' or it is not accessible!", type, filename);
-                logWarn("Keep {} database in default state!", type);
-            } else {
-                logInfo("{} database was successfully loaded from '{}' file", type, filename);
-            }
-        };
-
-        time_db_loader(_mountCurrentConfig.leap_seconds_filename, "leap seconds", _leapSecondsDB);
-        time_db_loader(_mountCurrentConfig.earth_orient_filename, "Earth orientation", _earthOrientDB);
+        updateIERSDatabase(IERS_DB_LEAPSECS);
+        updateIERSDatabase(IERS_DB_EARTH_ORIENT);
     }
 
     virtual ~MccMount()
@@ -211,6 +198,37 @@ public:
         _currentMeteo.store(meteo);
     }
 
+
+    bool updateIERSDatabase(IersDatabaseType type)
+    {
+        auto time_db_loader = [this](const std::string& filename, std::string_view type, auto& db) {
+            if (filename.empty()) {
+                logWarn("An empty {} filename! Skip and keep default values!", type);
+                return false;
+            }
+
+            bool ok = db.load(filename);
+            if (!ok) {
+                logError("CANNOT parse {} file '{}' or it is not accessible!", type, filename);
+                logWarn("Keep {} database in default state!", type);
+            } else {
+                logInfo("{} database was successfully loaded from '{}' file", type, filename);
+            }
+
+            return ok;
+        };
+
+        switch (type) {
+            case IERS_DB_LEAPSECS:
+                return time_db_loader(_mountCurrentConfig.leap_seconds_filename, "leap seconds", _leapSecondsDB);
+            case IERS_DB_EARTH_ORIENT:
+                return time_db_loader(_mountCurrentConfig.earth_orient_filename, "Earth orientation", _earthOrientDB);
+            default:
+                logError("Invalid type for IERS database!");
+                return false;
+        }
+    }
+
 protected:
     mount_config_t _mountCurrentConfig;
 
diff --git a/cxx/mount_astrom.h b/cxx/mount_astrom.h
index 66d0490..93dfea3 100644
--- a/cxx/mount_astrom.h
+++ b/cxx/mount_astrom.h
@@ -42,9 +42,8 @@ concept mcc_real_or_char_range =
 namespace mcc::astrom
 {
 
-// a time duration represented in radians (the precision is near 1 nanosecond)
-// typedef std::chrono::duration<double, std::ratio<134670467, 10000000000000000>> mcc_radsec_duration_t;
-typedef std::chrono::duration<double, std::ratio<134670467, 10000000000000000>> mcc_chrono_radians;
+// a time duration represented in radians (the precision is about 100 nanosecond for 10E8 secs (~1157 days))
+typedef std::chrono::duration<double, std::ratio<314159265358979, 4320000000000000000>> mcc_chrono_radians;
 
 
 // https://gssc.esa.int/navipedia/index.php?title=CEP_to_ITRF
diff --git a/cxx/tests/astrom_test.cpp b/cxx/tests/astrom_test.cpp
index 7d8b828..b897579 100644
--- a/cxx/tests/astrom_test.cpp
+++ b/cxx/tests/astrom_test.cpp
@@ -59,6 +59,15 @@ int main(int argc, char* argv[])
     auto st = mcc::astrom::mcc_julday(now, mjd);
     std::cout << "MJD for now: " << std::setprecision(19) << mjd << " (" << now << ")\n";
 
+    // double pres = 786.6;
+    // double temp = 0.0;
+    // double hum = 0.8;
+    // double A, B;
+
+    // erfa::eraRefco(pres, temp, hum, 0.5, &A, &B);
+    // const double rr = 180.0 / std::numbers::pi * 60.0;
+    // std::cout << "A(arcmin) = " << A * rr << "; B(arcmin) = " << B * rr << "\n";
+
 
     return ecode;
 }