@Override
    protected DateFormat initialValue() {
      //2016-03-11T10:42:36.376Z
      return new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXX");
    }
Indicates if audit log feature is enabled
ambari-server/src/main/java/org/apache/ambari/server/audit/AuditLoggerDefaultImpl.java