diff --git a/NumLib/TimeStepping/TimeInterval.cpp b/BaseLib/TimeInterval.cpp
similarity index 75%
rename from NumLib/TimeStepping/TimeInterval.cpp
rename to BaseLib/TimeInterval.cpp
index 19ec782c50f74a4101b9c300438176c5c1b26fec..f8e10f155f28bc37f0ff364640ca61742969cf9b 100644
--- a/NumLib/TimeStepping/TimeInterval.cpp
+++ b/BaseLib/TimeInterval.cpp
@@ -15,7 +15,7 @@
 
 #include "BaseLib/ConfigTree.h"
 
-namespace NumLib
+namespace BaseLib
 {
 std::unique_ptr<TimeInterval> createTimeInterval(
     BaseLib::ConfigTree const& config)
@@ -24,13 +24,13 @@ std::unique_ptr<TimeInterval> createTimeInterval(
     auto const& time_interval_config = config.getConfigSubtree("time_interval");
 
     const double start_time =
-        //! \ogs_file_param{prj__time_loop__processes__process__time_interval__start_time}
-        time_interval_config.getConfigParameter<double>("start_time");
+        //! \ogs_file_param{prj__time_loop__processes__process__time_interval__start}
+        time_interval_config.getConfigParameter<double>("start");
 
     const double end_time =
-        //! \ogs_file_param{prj__time_loop__processes__process__time_interval__end_time}
-        time_interval_config.getConfigParameter<double>("end_time");
+        //! \ogs_file_param{prj__time_loop__processes__process__time_interval__end}
+        time_interval_config.getConfigParameter<double>("end");
 
-    return std::make_unique<NumLib::TimeInterval>(start_time, end_time);
+    return std::make_unique<BaseLib::TimeInterval>(start_time, end_time);
 }
 }  // end of namespace
diff --git a/NumLib/TimeStepping/TimeInterval.h b/BaseLib/TimeInterval.h
similarity index 97%
rename from NumLib/TimeStepping/TimeInterval.h
rename to BaseLib/TimeInterval.h
index f873b1f49ded1b9488f5fd16bd746119e472d41a..f57a7ce28eaace8c4e43c85b1ee0307551a7af79 100644
--- a/NumLib/TimeStepping/TimeInterval.h
+++ b/BaseLib/TimeInterval.h
@@ -17,10 +17,7 @@
 namespace BaseLib
 {
 class ConfigTree;
-}
 
-namespace NumLib
-{
 /*!
  * Class for a time interval, which has a member to check whether the given time
  * is in this time interval.
diff --git a/Documentation/ProjectFile/prj/time_loop/processes/process/time_interval/t_end_time.md b/Documentation/ProjectFile/prj/time_loop/processes/process/time_interval/t_end.md
similarity index 100%
rename from Documentation/ProjectFile/prj/time_loop/processes/process/time_interval/t_end_time.md
rename to Documentation/ProjectFile/prj/time_loop/processes/process/time_interval/t_end.md
diff --git a/Documentation/ProjectFile/prj/time_loop/processes/process/time_interval/t_start_time.md b/Documentation/ProjectFile/prj/time_loop/processes/process/time_interval/t_start.md
similarity index 100%
rename from Documentation/ProjectFile/prj/time_loop/processes/process/time_interval/t_start_time.md
rename to Documentation/ProjectFile/prj/time_loop/processes/process/time_interval/t_start.md
diff --git a/ProcessLib/BoundaryCondition/CreateBoundaryCondition.cpp b/ProcessLib/BoundaryCondition/CreateBoundaryCondition.cpp
index 02407f68562b34f50a8100ac57b059de5892c783..fa3342bdf56955a0e3c6fed878508d94dcd6334d 100644
--- a/ProcessLib/BoundaryCondition/CreateBoundaryCondition.cpp
+++ b/ProcessLib/BoundaryCondition/CreateBoundaryCondition.cpp
@@ -22,7 +22,7 @@
 #include "PhaseFieldIrreversibleDamageOracleBoundaryCondition.h"
 #include "RobinBoundaryCondition.h"
 
-#include "NumLib/TimeStepping/TimeInterval.h"
+#include "BaseLib/TimeInterval.h"
 
 #ifdef OGS_USE_PYTHON
 #include "Python/PythonBoundaryCondition.h"
diff --git a/ProcessLib/BoundaryCondition/DirichletBoundaryConditionWithinTimeInterval.cpp b/ProcessLib/BoundaryCondition/DirichletBoundaryConditionWithinTimeInterval.cpp
index 209c787e6d4e2c15b861476b6a409953d323aaf1..1e355e3772e9a8f48ea90582549fc4fadfe3d033 100644
--- a/ProcessLib/BoundaryCondition/DirichletBoundaryConditionWithinTimeInterval.cpp
+++ b/ProcessLib/BoundaryCondition/DirichletBoundaryConditionWithinTimeInterval.cpp
@@ -16,10 +16,10 @@
 #include "DirichletBoundaryConditionAuxiliaryFunctions.h"
 
 #include "BaseLib/ConfigTree.h"
+#include "BaseLib/TimeInterval.h"
 
 #include "NumLib/DOF/LocalToGlobalIndexMap.h"
 #include "NumLib/IndexValueVector.h"
-#include "NumLib/TimeStepping/TimeInterval.h"
 
 #include "ProcessLib/Parameter/Parameter.h"
 #include "ProcessLib/Utils/ProcessUtils.h"
@@ -28,7 +28,7 @@ namespace ProcessLib
 {
 DirichletBoundaryConditionWithinTimeInterval::
     DirichletBoundaryConditionWithinTimeInterval(
-        std::unique_ptr<NumLib::TimeInterval> time_interval,
+        std::unique_ptr<BaseLib::TimeInterval> time_interval,
         Parameter<double> const& parameter, MeshLib::Mesh const& bc_mesh,
         NumLib::LocalToGlobalIndexMap const& dof_table_bulk,
         int const variable_id, int const component_id)
@@ -103,7 +103,7 @@ createDirichletBoundaryConditionWithinTimeInterval(
     config.peekConfigParameter<std::string>("time_interval");
 
     return std::make_unique<DirichletBoundaryConditionWithinTimeInterval>(
-        NumLib::createTimeInterval(config), param, bc_mesh, dof_table_bulk,
+        BaseLib::createTimeInterval(config), param, bc_mesh, dof_table_bulk,
         variable_id, component_id);
 }
 
diff --git a/ProcessLib/BoundaryCondition/DirichletBoundaryConditionWithinTimeInterval.h b/ProcessLib/BoundaryCondition/DirichletBoundaryConditionWithinTimeInterval.h
index 118a4e8e12493a29e24cf6cff0b01084af93918f..0d3c9022294fa8a1e25bb165943039e9403c1d1c 100644
--- a/ProcessLib/BoundaryCondition/DirichletBoundaryConditionWithinTimeInterval.h
+++ b/ProcessLib/BoundaryCondition/DirichletBoundaryConditionWithinTimeInterval.h
@@ -19,10 +19,6 @@
 namespace BaseLib
 {
 class ConfigTree;
-}
-
-namespace NumLib
-{
 class TimeInterval;
 }
 
@@ -36,7 +32,7 @@ class DirichletBoundaryConditionWithinTimeInterval final
 {
 public:
     DirichletBoundaryConditionWithinTimeInterval(
-        std::unique_ptr<NumLib::TimeInterval> time_interval,
+        std::unique_ptr<BaseLib::TimeInterval> time_interval,
         Parameter<double> const& parameter, MeshLib::Mesh const& bc_mesh,
         NumLib::LocalToGlobalIndexMap const& dof_table_bulk,
         int const variable_id, int const component_id);
@@ -53,7 +49,7 @@ private:
     int const _variable_id;
     int const _component_id;
 
-    std::unique_ptr<NumLib::TimeInterval> _time_interval;
+    std::unique_ptr<BaseLib::TimeInterval> _time_interval;
 };
 
 std::unique_ptr<DirichletBoundaryConditionWithinTimeInterval>
diff --git a/Tests/Data/Parabolic/LiquidFlow/TimeIntervalDirichletBC/TimeIntervalDirichletBC.prj b/Tests/Data/Parabolic/LiquidFlow/TimeIntervalDirichletBC/TimeIntervalDirichletBC.prj
index bad9a1db66128d8848a7cf30cd8fecca15e87362..3e66ccb32641338fca79a24c34d9d129167b2cd7 100644
--- a/Tests/Data/Parabolic/LiquidFlow/TimeIntervalDirichletBC/TimeIntervalDirichletBC.prj
+++ b/Tests/Data/Parabolic/LiquidFlow/TimeIntervalDirichletBC/TimeIntervalDirichletBC.prj
@@ -137,8 +137,8 @@
                     <type>DirichletWithinTimeInterval</type>
                     <parameter>bc_bottom</parameter>
                     <time_interval>
-                        <start_time> 0.0 </start_time>
-                        <end_time> 10.0 </end_time>
+                        <start> 0.0 </start>
+                        <end> 10.0 </end>
                     </time_interval>
                 </boundary_condition>
             </boundary_conditions>