diff --git a/mission/controller/acs/Igrf13Model.cpp b/mission/controller/acs/Igrf13Model.cpp
index 4ae7c93a..b15edada 100644
--- a/mission/controller/acs/Igrf13Model.cpp
+++ b/mission/controller/acs/Igrf13Model.cpp
@@ -69,7 +69,8 @@ void Igrf13Model::magFieldComp(const double longitude, const double gcLatitude,
   magFieldModel[1] *= -1;
   magFieldModel[2] *= (-1 / sin(theta));
 
-  double JD2000 = TimeSystems::convertUnixToJD2000(timeOfMagMeasurement);
+  double JD2000 = 0;
+  Clock::convertTimevalToJD2000(timeOfMagMeasurement, &JD2000);
   double UT1 = JD2000 / 36525.;
 
   double gst =
@@ -93,7 +94,8 @@ void Igrf13Model::magFieldComp(const double longitude, const double gcLatitude,
 
 void Igrf13Model::updateCoeffGH(timeval timeOfMagMeasurement) {
   double JD2000Igrf = (2458850.0 - 2451545);  // Begin of IGRF-13 (2020-01-01,00:00:00) in JD2000
-  double JD2000 = TimeSystems::convertUnixToJD2000(timeOfMagMeasurement);
+  double JD2000 = 0;
+  Clock::convertTimevalToJD2000(timeOfMagMeasurement, &JD2000);
   double days = ceil(JD2000 - JD2000Igrf);
   for (int i = 0; i <= igrfOrder; i++) {
     for (int j = 0; j <= (igrfOrder - 1); j++) {
diff --git a/mission/controller/acs/Igrf13Model.h b/mission/controller/acs/Igrf13Model.h
index 9a7feb34..f0936b7f 100644
--- a/mission/controller/acs/Igrf13Model.h
+++ b/mission/controller/acs/Igrf13Model.h
@@ -16,11 +16,11 @@
 #ifndef IGRF13MODEL_H_
 #define IGRF13MODEL_H_
 
-#include <fsfw/src/fsfw/globalfunctions/TimeSystems.h>
 #include <fsfw/src/fsfw/globalfunctions/constants.h>
 #include <fsfw/src/fsfw/globalfunctions/math/MatrixOperations.h>
 #include <fsfw/src/fsfw/globalfunctions/math/QuaternionOperations.h>
 #include <fsfw/src/fsfw/globalfunctions/math/VectorOperations.h>
+#include <fsfw/src/fsfw/timemanager/Clock.h>
 
 #include <cmath>
 
diff --git a/mission/controller/acs/SensorProcessing.cpp b/mission/controller/acs/SensorProcessing.cpp
index ac82e891..46be5db2 100644
--- a/mission/controller/acs/SensorProcessing.cpp
+++ b/mission/controller/acs/SensorProcessing.cpp
@@ -180,7 +180,8 @@ void SensorProcessing::processSus(
     const AcsParameters::SunModelParameters *sunModelParameters,
     acsctrl::SusDataProcessed *susDataProcessed) {
   /* -------- Sun Model Direction (IJK frame) ------- */
-  double JD2000 = TimeSystems::convertUnixToJD2000(timeAbsolute);
+  double JD2000 = 0;
+  Clock::convertTimevalToJD2000(timeAbsolute, &JD2000);
 
   // Julean Centuries
   double sunIjkModel[3] = {0.0, 0.0, 0.0};
diff --git a/mission/controller/acs/SensorProcessing.h b/mission/controller/acs/SensorProcessing.h
index e5efba71..baa43117 100644
--- a/mission/controller/acs/SensorProcessing.h
+++ b/mission/controller/acs/SensorProcessing.h
@@ -4,13 +4,13 @@
 #include <common/config/eive/resultClassIds.h>
 #include <fsfw/coordinates/CoordinateTransformations.h>
 #include <fsfw/datapool/PoolReadGuard.h>
-#include <fsfw/globalfunctions/TimeSystems.h>
 #include <fsfw/globalfunctions/constants.h>
 #include <fsfw/globalfunctions/math/MatrixOperations.h>
 #include <fsfw/globalfunctions/math/QuaternionOperations.h>
 #include <fsfw/globalfunctions/math/VectorOperations.h>
 #include <fsfw/globalfunctions/timevalOperations.h>
 #include <fsfw/returnvalues/returnvalue.h>
+#include <fsfw/timemanager/Clock.h>
 #include <mission/acs/defs.h>
 #include <mission/controller/acs/AcsParameters.h>
 #include <mission/controller/acs/Igrf13Model.h>