diff --git a/DEMSystems/DEMSystem/DEMSystem.hpp b/DEMSystems/DEMSystem/DEMSystem.hpp
index ee3c6ec3..023b6481 100644
--- a/DEMSystems/DEMSystem/DEMSystem.hpp
+++ b/DEMSystems/DEMSystem/DEMSystem.hpp
@@ -144,7 +144,13 @@ public:
 	bool beforeIteration() = 0;
 
 	virtual 
-	bool iterate(int32 n, real timeToWrite, word timeName) = 0;
+	bool iterate(
+		real upToTime, 
+		real timeToWrite, 
+		word timeName) = 0;
+
+	virtual 
+	bool iterate(real upToTime) = 0;
 	
 	
 
diff --git a/DEMSystems/sphereDEMSystem/sphereDEMSystem.cpp b/DEMSystems/sphereDEMSystem/sphereDEMSystem.cpp
index f3836b2c..c230a9ce 100644
--- a/DEMSystems/sphereDEMSystem/sphereDEMSystem.cpp
+++ b/DEMSystems/sphereDEMSystem/sphereDEMSystem.cpp
@@ -20,6 +20,36 @@ Licence:
 
 #include "sphereDEMSystem.hpp"
 
+void pFlow::sphereDEMSystem::loop()
+{
+
+	do 
+	{
+		Control().timers().start();
+
+		geometry_->beforeIteration();
+		
+		interaction_->beforeIteration();
+
+		particles_->beforeIteration();
+		
+		
+		interaction_->iterate();
+
+		particles_->iterate();
+
+		geometry_->iterate();
+
+		particles_->afterIteration();
+		
+		geometry_->afterIteration();
+		
+
+		Control().timers().end();
+
+	}while(Control()++);
+
+}
 
 pFlow::sphereDEMSystem::sphereDEMSystem(
 		word  demSystemName,
@@ -161,10 +191,23 @@ bool pFlow::sphereDEMSystem::beforeIteration()
 
 
 bool pFlow::sphereDEMSystem::iterate(
-	int32 n, 
+	real upToTime, 
 	real timeToWrite, 
 	word timeName) 
 {
+
+	Control().time().setEndTime(upToTime);
+	Control().time().setOutputToFile(timeToWrite, timeName);
+	
+	loop();
+
+	return true;
+}
+
+bool pFlow::sphereDEMSystem::iterate(real upToTime)
+{
+	Control().time().setEndTime(upToTime);
+	loop();
 	return true;
 }
 
diff --git a/DEMSystems/sphereDEMSystem/sphereDEMSystem.hpp b/DEMSystems/sphereDEMSystem/sphereDEMSystem.hpp
index 3272a6e1..2aa2d07f 100644
--- a/DEMSystems/sphereDEMSystem/sphereDEMSystem.hpp
+++ b/DEMSystems/sphereDEMSystem/sphereDEMSystem.hpp
@@ -82,6 +82,8 @@ protected:
 		return interaction_();
 	} 
 
+	void loop();
+
 public:
 
 	TypeInfo("sphereDEMSystem");
@@ -128,7 +130,12 @@ public:
 
 	bool beforeIteration() override;
 
-	bool iterate(int32 n, real timeToWrite, word timeName) override;
+	bool iterate(
+		real upToTime, 
+		real timeToWrite, 
+		word timeName) override;
+
+	bool iterate(real upToTime) override;
 	
 	real maxBounndingSphereSize()const override;
 
diff --git a/src/phasicFlow/repository/Time/timeControl.cpp b/src/phasicFlow/repository/Time/timeControl.cpp
index 7c5fd087..5308d5c7 100644
--- a/src/phasicFlow/repository/Time/timeControl.cpp
+++ b/src/phasicFlow/repository/Time/timeControl.cpp
@@ -102,19 +102,27 @@ pFlow::timeControl::timeControl(
 void pFlow::timeControl::checkForOutputToFile()
 {
 	
-	if(managedExternaly_) return;
-
 	bool save = false;
-	
-	if ( abs(currentTime_ - lastSaved_ - saveInterval_) < 0.5 * dt_ )
-	{	
-		lastSaved_ = currentTime_;
-		save = true;
-	}
-	else if( abs(currentTime_ - lastSaved_) < min( pow(10.0,-1.0*timePrecision_), 0.5 *dt_) )
+	if(managedExternaly_)
 	{
-		lastSaved_ = currentTime_;
-		save = true;
+		if( abs(currentTime_-writeTime_) < 0.5*dt_)
+		{
+			save = true;
+			lastSaved_ = currentTime_;
+		}
+	}
+	else
+	{
+		if ( abs(currentTime_ - lastSaved_ - saveInterval_) < 0.5 * dt_ )
+		{	
+			lastSaved_ = currentTime_;
+			save = true;
+		}
+		else if( abs(currentTime_ - lastSaved_) < min( pow(10.0,-1.0*timePrecision_), 0.5 *dt_) )
+		{
+			lastSaved_ = currentTime_;
+			save = true;
+		}	
 	}
 
 	outputToFile_ = save;
diff --git a/src/phasicFlow/repository/Time/timeControl.hpp b/src/phasicFlow/repository/Time/timeControl.hpp
index 51491ce9..b90d8d42 100644
--- a/src/phasicFlow/repository/Time/timeControl.hpp
+++ b/src/phasicFlow/repository/Time/timeControl.hpp
@@ -67,7 +67,9 @@ protected:
 
 	bool  managedExternaly_ = false;
 
-	word  timeName_ = "wrongSettings";
+	word  timeName_ = "wrongSettings"; // for managedExternamly
+
+	real 	writeTime_ = 0; // for managedExternamly
 
 	realStridedRange  timersReportInterval_;
 
@@ -108,6 +110,15 @@ public:
 		return tmp;
 	}
 
+	void setEndTime(real eT)
+	{
+		if(managedExternaly_)
+		{
+			endTime_ = eT;
+		}
+
+	}
+
 	real startTime()const
 	{
 		return startTime_;
@@ -141,6 +152,7 @@ public:
 	bool finished()const
 	{
 		if( currentTime_ >= endTime_ ) return true;
+		if( abs(currentTime_-endTime_) < 0.5*dt_ )return true;
 		return false;
 	}
 
@@ -151,6 +163,15 @@ public:
 
 	bool timersReportTime()const;
 	
+	bool setOutputToFile(real writeTime, const word& timeName)
+	{
+		if(managedExternaly_)
+		{
+			timeName_ = timeName;
+			writeTime_ = writeTime;
+		}
+		return true;
+	}
 
 	bool operator ++(int)
 	{