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");
Index: lams_monitoring/web/includes/javascript/monitorLesson.js
===================================================================
diff -u -r312140979ac91708e16d2b57c98f53c13e99ab24 -rd5a65c627bdbb1f30d76de7c553d6c7cf448a9fe
--- lams_monitoring/web/includes/javascript/monitorLesson.js	(.../monitorLesson.js)	(revision 312140979ac91708e16d2b57c98f53c13e99ab24)
+++ lams_monitoring/web/includes/javascript/monitorLesson.js	(.../monitorLesson.js)	(revision d5a65c627bdbb1f30d76de7c553d6c7cf448a9fe)
@@ -435,15 +435,15 @@
 					lessonStateChanger.hide();
 					break;
 				//started lesson
-				default: 		
+				default: 	
+					startDateField.text("").css('display','none'); // we may have just started the lesson and needed to clear the scheduled date message
 				 	if ( response.finishDate ) {
 						scheduleControls.css('display','inline');
 						$("#lessonStartApply").css('display','none');
 				 		lessonFinishDateSpan.text(LABELS.LESSON_FINISH.replace("%0",response.finishDate)).css('display','inline');
 						$("#scheduleDisableLessonButton").html(LABELS.RESCHEDULE);
 				 	} else {
 						scheduleControls.css('display','none');
-						startDateField.text(response.startDate).hide();
 						$("#scheduleDisableLessonButton").html(LABELS.SCHEDULE);
 				 		lessonFinishDateSpan.text("").css('display','none');
 				 	}
@@ -469,7 +469,7 @@
 function checkScheduleDate(startDateString, endDateString) {
 	var startDate = startDateString && startDateString > "" ? Date.parse(startDateString) : 0;
 	var endDate =  endDateString && endDateString > "" ? Date.parse(endDateString) : 0;
-	return ( endDate > startDate );
+	return ( endDate == 0 || startDate < endDate );
 }
 
 function scheduleLesson(){