diff --git a/data-prepper-plugins/s3-sink/src/main/java/org/opensearch/dataprepper/plugins/sink/s3/configuration/ObjectKeyOptions.java b/data-prepper-plugins/s3-sink/src/main/java/org/opensearch/dataprepper/plugins/sink/s3/configuration/ObjectKeyOptions.java
index bd0b07cf1a..bc2c93eb3f 100644
--- a/data-prepper-plugins/s3-sink/src/main/java/org/opensearch/dataprepper/plugins/sink/s3/configuration/ObjectKeyOptions.java
+++ b/data-prepper-plugins/s3-sink/src/main/java/org/opensearch/dataprepper/plugins/sink/s3/configuration/ObjectKeyOptions.java
@@ -11,7 +11,7 @@
  * An implementation class of path prefix and file pattern configuration Options
  */
 public class ObjectKeyOptions {
-    private static final String DEFAULT_OBJECT_NAME_PATTERN = "events-%{yyyy-MM-dd'T'hh-mm-ss}";
+    private static final String DEFAULT_OBJECT_NAME_PATTERN = "events-%{yyyy-MM-dd'T'HH-mm-ss'Z'}";
 
     @JsonProperty("path_prefix")
     private String pathPrefix;
diff --git a/data-prepper-plugins/s3-sink/src/test/java/org/opensearch/dataprepper/plugins/sink/s3/configuration/ObjectKeyOptionsTest.java b/data-prepper-plugins/s3-sink/src/test/java/org/opensearch/dataprepper/plugins/sink/s3/configuration/ObjectKeyOptionsTest.java
index 5f52015eaf..6dd3f9c8bf 100644
--- a/data-prepper-plugins/s3-sink/src/test/java/org/opensearch/dataprepper/plugins/sink/s3/configuration/ObjectKeyOptionsTest.java
+++ b/data-prepper-plugins/s3-sink/src/test/java/org/opensearch/dataprepper/plugins/sink/s3/configuration/ObjectKeyOptionsTest.java
@@ -12,7 +12,7 @@
 
 class ObjectKeyOptionsTest {
 
-    private static final String DEFAULT_FILE_PATTERN = "events-%{yyyy-MM-dd'T'hh-mm-ss}";
+    private static final String DEFAULT_FILE_PATTERN = "events-%{yyyy-MM-dd'T'HH-mm-ss'Z'}";
 
     @Test
     void default_file_pattern_test() {