[fix] handle invalid date in get_retirement_date
diff --git a/erpnext/hr/doctype/employee/employee.py b/erpnext/hr/doctype/employee/employee.py
index a2bb10c..7b5c6c1 100644
--- a/erpnext/hr/doctype/employee/employee.py
+++ b/erpnext/hr/doctype/employee/employee.py
@@ -158,8 +158,13 @@
 	import datetime
 	ret = {}
 	if date_of_birth:
-		dt = getdate(date_of_birth) + datetime.timedelta(21915)
-		ret = {'date_of_retirement': dt.strftime('%Y-%m-%d')}
+		try:
+			dt = getdate(date_of_birth) + datetime.timedelta(21915)
+			ret = {'date_of_retirement': dt.strftime('%Y-%m-%d')}
+		except ValueError:
+			# invalid date
+			ret = {}
+
 	return ret
 
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