public void setCreatedAt(java.util.Date createdAt) {
        this.createdAt = createdAt;
    }
<p>
The timestamp when the operation was initialized (<code>1479816991.349</code>).
</p>

@param createdAt
       The timestamp when the operation was initialized (<code>1479816991.349</code>).
aws-java-sdk-lightsail/src/main/java/com/amazonaws/services/lightsail/model/Operation.java