fixed typo
diff --git a/erpnext/crm/doctype/appointment/appointment.json b/erpnext/crm/doctype/appointment/appointment.json
index b2fe7b9..2d695f31 100644
--- a/erpnext/crm/doctype/appointment/appointment.json
+++ b/erpnext/crm/doctype/appointment/appointment.json
@@ -13,7 +13,7 @@
   "customer_skype",
   "customer_details",
   "lead",
-  "calender_event"
+  "calendar_event"
  ],
  "fields": [
   {
@@ -67,14 +67,13 @@
    "reqd": 1
   },
   {
-   "fieldname": "calender_event",
+   "fieldname": "calendar_event",
    "fieldtype": "Link",
-   "label": "Calender Event",
-   "options": "Event",
-   "reqd": 1
+   "label": "Calendar Event",
+   "options": "Event"
   }
  ],
- "modified": "2019-09-12 10:42:47.841841",
+ "modified": "2019-09-13 15:25:49.362246",
  "modified_by": "Administrator",
  "module": "CRM",
  "name": "Appointment",