Index: lams_central/web/includes/javascript/addLesson.js
===================================================================
diff -u -ra4002ee13a835e74c08e3d657494f1c97b531013 -rd5a65c627bdbb1f30d76de7c553d6c7cf448a9fe
--- lams_central/web/includes/javascript/addLesson.js	(.../addLesson.js)	(revision a4002ee13a835e74c08e3d657494f1c97b531013)
+++ lams_central/web/includes/javascript/addLesson.js	(.../addLesson.js)	(revision d5a65c627bdbb1f30d76de7c553d6c7cf448a9fe)
@@ -275,7 +275,9 @@
 function checkScheduleDate() {
 	var startDate = $('#schedulingDatetimeField').val() > "" ? Date.parse($('#schedulingDatetimeField').val()) : 0;
 	var endDate = $('#schedulingEndDatetimeField').val() > "" ? Date.parse($('#schedulingEndDatetimeField').val()) : 0;
-	if ( endDate - startDate ) {
+	console.log("startDate"+startDate+"endDate"+endDate);
+	console.log(endDate - startDate);
+	if ( endDate > 0 && startDate >= endDate  ) {
 		$("#schedulingError").css("display","block");
 	} else {
 		$("#schedulingError").css("display","none");