diff --git a/fluentd/files/match/elasticsearch.conf b/fluentd/files/match/elasticsearch.conf
index ff015c8..f5024c5 100644
--- a/fluentd/files/match/elasticsearch.conf
+++ b/fluentd/files/match/elasticsearch.conf
@@ -8,7 +8,7 @@
   time_key_exclude_timestamp true
   logstash_format true
   logstash_prefix {{ values.get("es_index_name", "log") }}
-  logstash_dateformat %Y%m%d
+  logstash_dateformat %Y.%m.%d
   flush_interval {{ values.get("flush_interval", "10s") }}
   request_timeout {{ values.get("request_timeout", "10s") }}
 {%- if values.get("buffer") %}