fix: Patient Appointment Calendar (#15684)

diff --git a/erpnext/healthcare/doctype/patient_appointment/patient_appointment.py b/erpnext/healthcare/doctype/patient_appointment/patient_appointment.py
index 7d948b8..5364031 100755
--- a/erpnext/healthcare/doctype/patient_appointment/patient_appointment.py
+++ b/erpnext/healthcare/doctype/patient_appointment/patient_appointment.py
@@ -339,13 +339,13 @@
 
 	data = frappe.db.sql("""select name, patient, practitioner, status,
 		duration, timestamp(appointment_date, appointment_time) as
-		'appointment_date' from `tabPatient Appointment` where
+		'start' from `tabPatient Appointment` where
 		(appointment_date between %(start)s and %(end)s)
 		and docstatus < 2 {conditions}""".format(conditions=conditions),
 		{"start": start, "end": end}, as_dict=True, update={"allDay": 0})
 
 	for item in data:
-		item.appointment_datetime = item.appointment_date + datetime.timedelta(minutes = item.duration)
+		item.end = item.start + datetime.timedelta(minutes = item.duration)
 
 	return data
 
diff --git a/erpnext/healthcare/doctype/patient_appointment/patient_appointment_calendar.js b/erpnext/healthcare/doctype/patient_appointment/patient_appointment_calendar.js
index fc674a8..2249d2a 100644
--- a/erpnext/healthcare/doctype/patient_appointment/patient_appointment_calendar.js
+++ b/erpnext/healthcare/doctype/patient_appointment/patient_appointment_calendar.js
@@ -10,37 +10,5 @@
 	},
 	order_by: "appointment_date",
 	gantt: true,
-	get_events_method: "erpnext.healthcare.doctype.patient_appointment.patient_appointment.get_events",
-	filters: [
-		{
-			'fieldtype': 'Link',
-			'fieldname': 'practitioner',
-			'options': 'Healthcare Practitioner',
-			'label': __('Healthcare Practitioner')
-		},
-		{
-			'fieldtype': 'Link',
-			'fieldname': 'patient',
-			'options': 'Patient',
-			'label': __('Patient')
-		},
-		{
-			'fieldtype': 'Link',
-			'fieldname': 'appointment_type',
-			'options': 'Appointment Type',
-			'label': __('Appointment Type')
-		},
-		{
-			'fieldtype': 'Link',
-			'fieldname': 'department',
-			'options': 'Medical Department',
-			'label': __('Department')
-		},
-		{
-			'fieldtype': 'Select',
-			'fieldname': 'status',
-			'options': 'Scheduled\nOpen\nClosed\nPending',
-			'label': __('Status')
-		}
-	]
+	get_events_method: "erpnext.healthcare.doctype.patient_appointment.patient_appointment.get_events"
 };