diff --git a/viecpro_typesense/collections.py b/viecpro_typesense/collections.py
index b003809..6ba909a 100644
--- a/viecpro_typesense/collections.py
+++ b/viecpro_typesense/collections.py
@@ -38,13 +38,13 @@ def collection_factory(name, fields, config):
 
 def get_start_year_or_0(instance):
     if instance.start_date is not None:
-        return instance.start_date.year()
+        return instance.start_date.year
     return 0
 
 
 def get_end_year_or_5000(instance):
     if instance.end_date is not None:
-        return instance.end_date.year()
+        return instance.end_date.year
     return 5000