diff --git a/gs-carcolor/src/main/java/org/genericsystem/carcolor/GSUserGuide.java b/gs-carcolor/src/main/java/org/genericsystem/carcolor/GSUserGuide.java
index 1e51f6e4d..b0aec48ef 100644
--- a/gs-carcolor/src/main/java/org/genericsystem/carcolor/GSUserGuide.java
+++ b/gs-carcolor/src/main/java/org/genericsystem/carcolor/GSUserGuide.java
@@ -54,7 +54,7 @@ public GSUserGuide(Tag parent) {
 										HtmlLi li1 = new HtmlLi(this);
 										HtmlLi li2 = new HtmlLi(this);
 										HtmlLi li3 = new HtmlLi(this);
-										li1.setText("Add new color");
+										li1.setText("Add new color of any CSS color style (ex : Black, rgb(0,0,0), #000000, ...)");
 										li2.setText("Select car in the ComboBox");
 										li3.setText("Use \"add Button\" to update data");
 									}
diff --git a/gs-common/src/main/java/org/genericsystem/common/AbstractCache.java b/gs-common/src/main/java/org/genericsystem/common/AbstractCache.java
index e34c024de..e2ad2d7ea 100644
--- a/gs-common/src/main/java/org/genericsystem/common/AbstractCache.java
+++ b/gs-common/src/main/java/org/genericsystem/common/AbstractCache.java
@@ -71,6 +71,7 @@ public final void stop() {
 	protected final ObjectProperty<IDifferential<Generic>> transactionProperty;
 	protected final ObjectProperty<Differential> differentialProperty = new SimpleObjectProperty<>();;
 	private ObservableIntegerValue cacheLevel;
+	private ObservableLongValue ts;
 	private final ContextEventListener<Generic> listener;
 	private Map<Generic, ObservableList<Generic>> dependenciesAsOservableListCacheMap = new HashMap<>();
 
@@ -100,7 +101,7 @@ public AbstractCache(Root root, ContextEventListener<Generic> listener) {
 		this.listener = listener;
 		transactionProperty = new SimpleObjectProperty<>(buildTransaction());
 		cacheLevel = Bindings.createIntegerBinding(() -> differentialProperty.get().getCacheLevel(), differentialProperty);
-
+		ts = Bindings.createLongBinding(() -> transactionProperty.get().getTs(), transactionProperty);
 		initialize();
 	}
 
@@ -124,6 +125,11 @@ public long getTs() {
 		return getTransaction().getTs();
 	}
 
+	@Override
+	public ObservableLongValue getTsObservableValue() {
+		return ts;
+	}
+
 	@Override
 	public Snapshot<Generic> getDependencies(Generic generic) {
 		return getDifferential().getDependencies(generic);
diff --git a/gs-defaults/src/main/java/org/genericsystem/defaults/DefaultCache.java b/gs-defaults/src/main/java/org/genericsystem/defaults/DefaultCache.java
index 5c369f995..4ad3dfcca 100644
--- a/gs-defaults/src/main/java/org/genericsystem/defaults/DefaultCache.java
+++ b/gs-defaults/src/main/java/org/genericsystem/defaults/DefaultCache.java
@@ -6,6 +6,7 @@
 import org.genericsystem.api.core.exceptions.ConcurrencyControlException;
 
 import javafx.beans.value.ObservableIntegerValue;
+import javafx.beans.value.ObservableLongValue;
 
 /**
  * @author Nicolas Feybesse
@@ -42,5 +43,7 @@ public interface DefaultCache<T extends DefaultGeneric<T>> extends DefaultContex
 
 	ObservableIntegerValue getCacheLevelObservableValue();
 
+	ObservableLongValue getTsObservableValue();
+
 	boolean contains(T generic);
 }
diff --git a/gs-reactor/src/main/java/org/genericsystem/reactor/Context.java b/gs-reactor/src/main/java/org/genericsystem/reactor/Context.java
index 25f746563..7ff093413 100644
--- a/gs-reactor/src/main/java/org/genericsystem/reactor/Context.java
+++ b/gs-reactor/src/main/java/org/genericsystem/reactor/Context.java
@@ -14,6 +14,7 @@
 import javafx.beans.property.Property;
 import javafx.beans.property.SimpleObjectProperty;
 import javafx.beans.value.ObservableIntegerValue;
+import javafx.beans.value.ObservableLongValue;
 import javafx.beans.value.ObservableValue;
 import javafx.collections.ObservableList;
 
@@ -163,6 +164,11 @@ public ObservableIntegerValue getCacheLevelObservableValue() {
 		return getGeneric().getCurrentCache().getCacheLevelObservableValue();
 	}
 
+	public ObservableLongValue getTsObservableValue() {
+
+		return getGeneric().getCurrentCache().getTsObservableValue();
+	}
+
 	public void mount() {
 		getGeneric().getCurrentCache().mount();
 	}
diff --git a/gs-reactor/src/main/java/org/genericsystem/reactor/gs/GSMonitor.java b/gs-reactor/src/main/java/org/genericsystem/reactor/gs/GSMonitor.java
index 87235c478..fec954393 100644
--- a/gs-reactor/src/main/java/org/genericsystem/reactor/gs/GSMonitor.java
+++ b/gs-reactor/src/main/java/org/genericsystem/reactor/gs/GSMonitor.java
@@ -1,8 +1,18 @@
 package org.genericsystem.reactor.gs;
 
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
+import java.util.Date;
+
+import org.genericsystem.common.Statics;
 import org.genericsystem.reactor.Context;
 import org.genericsystem.reactor.Tag;
 import org.genericsystem.reactor.gstag.HtmlButton;
+import org.genericsystem.reactor.gstag.HtmlLabel;
+
+import javafx.beans.binding.Bindings;
 
 public class GSMonitor extends GSDiv {
 
@@ -26,12 +36,17 @@ public GSMonitor(Tag parent, FlexDirection direction) {
 				bindAction(Context::cancel);
 			}
 		};
-		// new HtmlButton(this) {
-		// {
-		// setText("traverse");
-		// bindAction(Context::traverse);
-		// }
-		// };
+		new HtmlLabel(this) {
+			{
+				bindText(context -> Bindings.createStringBinding(() -> {
+					Long tsMs = (Long) context.getTsObservableValue().getValue() / Statics.MILLI_TO_NANOSECONDS;
+					Date dateMs = new Date(tsMs);
+					Instant instant = Instant.ofEpochMilli(dateMs.getTime());
+					LocalDateTime ldt = LocalDateTime.ofInstant(instant, ZoneOffset.systemDefault());
+					return "Last update : " + ldt.format(DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss"));
+				}, context.getTsObservableValue()));
+			}
+		};
 		// new GSButton(this) {
 		// {
 		// setText("Collect");