public void setCreatedAt(java.util.Date createdAt) {
        this.createdAt = createdAt;
    }
<p>
Timestamp which tells creation time of the package version.
</p>

@param createdAt
       Timestamp which tells creation time of the package version.
aws-java-sdk-elasticsearch/src/main/java/com/amazonaws/services/elasticsearch/model/PackageVersionHistory.java