diff --git a/dev-upgrade/elastic/logstash-ngx.yaml b/dev-upgrade/elastic/logstash-ngx.yaml
index 06d9863..3e586a5 100644
--- a/dev-upgrade/elastic/logstash-ngx.yaml
+++ b/dev-upgrade/elastic/logstash-ngx.yaml
@@ -11,6 +11,10 @@ data:
     }
 
     filter {
+      date {
+        match => [ "start_time", "dd/MMM/yyyy:HH:mm:ss Z" ]
+        target => "@timestamp"
+      }
       mutate {
         add_field => { "env" => "%{[tags][0]}" }
         remove_field => [ "tags" ]