diff --git a/etemplate/js/et2_widget_gantt.js b/etemplate/js/et2_widget_gantt.js
index aae4bd5c59..9413ce7093 100644
--- a/etemplate/js/et2_widget_gantt.js
+++ b/etemplate/js/et2_widget_gantt.js
@@ -275,6 +275,9 @@ var et2_gantt = et2_valueWidget.extend([et2_IResizeable,et2_IInput],
 
 		// Clear previous value
 		this.gantt.clearAll();
+		
+		// Clear the end date, or previous end date may break time scale
+		this.gantt.config.end_date = null;
 
 		if(value.duration_unit)
 		{