Initial JS setup
diff --git a/erpnext/crm/doctype/opportunity/opportunity_calendar.js b/erpnext/crm/doctype/opportunity/opportunity_calendar.js
new file mode 100644
index 0000000..983be9b
--- /dev/null
+++ b/erpnext/crm/doctype/opportunity/opportunity_calendar.js
@@ -0,0 +1,12 @@
+// Copyright (c) 2020, Frappe Technologies Pvt. Ltd. and Contributors
+// License: GNU General Public License v3. See license.txt
+frappe.views.calendar["Opportunity"] = {
+	field_map: {
+		"start": "contact_date",
+		"end": "contact_date",
+		"id": "name",
+		"title": "customer_name",
+		"allDay": "allDay"
+	},
+    get_events_method: 'frappe.desk.doctype.event.event.get_events'
+}