diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/LeftTasksTreeRow.java b/ganttzk/src/main/java/org/zkoss/ganttz/LeftTasksTreeRow.java
index cd7ed2a09..7e583174a 100644
--- a/ganttzk/src/main/java/org/zkoss/ganttz/LeftTasksTreeRow.java
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/LeftTasksTreeRow.java
@@ -349,7 +349,7 @@ public class LeftTasksTreeRow extends GenericForwardComposer {
     public void updateBean() {
         Date begin = getStartDateBox().getValue();
         task.setName(getNameBox().getValue());
-        task.setBeginDate(begin);
+        task.moveTo(begin);
     }
 
     private void updateComponents() {