order_by for gantt error fix (#13752)

diff --git a/erpnext/education/doctype/course_schedule/course_schedule_calendar.js b/erpnext/education/doctype/course_schedule/course_schedule_calendar.js
index 4fb6913..803527e 100644
--- a/erpnext/education/doctype/course_schedule/course_schedule_calendar.js
+++ b/erpnext/education/doctype/course_schedule/course_schedule_calendar.js
@@ -8,7 +8,7 @@
 		"allDay": "allDay"
 	},
 	gantt: false,
-	order_by: "from_time",
+	order_by: "schedule_date",
 	filters: [
 		{
 			"fieldtype": "Link",
diff --git a/erpnext/healthcare/doctype/patient_appointment/patient_appointment_calendar.js b/erpnext/healthcare/doctype/patient_appointment/patient_appointment_calendar.js
index 2905949..7221423 100644
--- a/erpnext/healthcare/doctype/patient_appointment/patient_appointment_calendar.js
+++ b/erpnext/healthcare/doctype/patient_appointment/patient_appointment_calendar.js
@@ -8,6 +8,7 @@
 		"allDay": "allDay",
 		"eventColor": "color"
 	},
+	order_by: "appointment_date",
 	gantt: true,
 	get_events_method: "erpnext.healthcare.doctype.patient_appointment.patient_appointment.get_events",
 	filters: [